diff --git a/extensions/fablabchemnitz/box_maker_conical/box_maker_conical.inx b/extensions/fablabchemnitz/box_maker_conical/box_maker_conical.inx
index 910b63ac..fb39dc2f 100644
--- a/extensions/fablabchemnitz/box_maker_conical/box_maker_conical.inx
+++ b/extensions/fablabchemnitz/box_maker_conical/box_maker_conical.inx
@@ -5,11 +5,7 @@
     <param name="unit" type="optiongroup" appearance="combo" gui-text="Unit">
         <option value="mm">mm</option>
         <option value="cm">cm</option>
-        <option value="m">m</option>
-        <option value="km">km</option>
         <option value="in">in</option>
-        <option value="ft">ft</option>
-        <option value="yd">yd</option>
         <option value="pt">pt</option>
         <option value="px">px</option>
         <option value="pc">pc</option>
diff --git a/extensions/fablabchemnitz/box_maker_elliptical_box/box_maker_elliptical_box.inx b/extensions/fablabchemnitz/box_maker_elliptical_box/box_maker_elliptical_box.inx
index 76c27e32..22bc6c4a 100644
--- a/extensions/fablabchemnitz/box_maker_elliptical_box/box_maker_elliptical_box.inx
+++ b/extensions/fablabchemnitz/box_maker_elliptical_box/box_maker_elliptical_box.inx
@@ -5,11 +5,7 @@
 	<param name="unit" type="optiongroup" appearance="combo" gui-text="Unit">
 		<option value="mm">mm</option>
 		<option value="cm">cm</option>
-		<option value="m">m</option>
-		<option value="km">km</option>
 		<option value="in">in</option>
-		<option value="ft">ft</option>
-		<option value="yd">yd</option>
 		<option value="pt">pt</option>
 		<option value="px">px</option>
 		<option value="pc">pc</option>
diff --git a/extensions/fablabchemnitz/box_maker_elliptical_cone/box_maker_elliptical_cone.inx b/extensions/fablabchemnitz/box_maker_elliptical_cone/box_maker_elliptical_cone.inx
index 94c79e2c..e225aa60 100644
--- a/extensions/fablabchemnitz/box_maker_elliptical_cone/box_maker_elliptical_cone.inx
+++ b/extensions/fablabchemnitz/box_maker_elliptical_cone/box_maker_elliptical_cone.inx
@@ -5,11 +5,7 @@
     <param name="unit" type="optiongroup" appearance="combo" gui-text="Unit">
         <option value="mm">mm</option>
         <option value="cm">cm</option>
-        <option value="m">m</option>
-        <option value="km">km</option>
         <option value="in">in</option>
-        <option value="ft">ft</option>
-        <option value="yd">yd</option>
         <option value="pt">pt</option>
         <option value="px">px</option>
         <option value="pc">pc</option>
diff --git a/extensions/fablabchemnitz/box_maker_generic_generator/box_maker_generic_generator.inx b/extensions/fablabchemnitz/box_maker_generic_generator/box_maker_generic_generator.inx
index a4962a54..3f5630b0 100644
--- a/extensions/fablabchemnitz/box_maker_generic_generator/box_maker_generic_generator.inx
+++ b/extensions/fablabchemnitz/box_maker_generic_generator/box_maker_generic_generator.inx
@@ -7,11 +7,7 @@
 			<param name="unit" type="optiongroup" appearance="combo" gui-text="Unit">
 				<option value="mm">mm</option>
 				<option value="cm">cm</option>
-				<option value="m">m</option>
-				<option value="km">km</option>
 				<option value="in">in</option>
-				<option value="ft">ft</option>
-				<option value="yd">yd</option>
 				<option value="pt">pt</option>
 				<option value="px">px</option>
 				<option value="pc">pc</option>
diff --git a/extensions/fablabchemnitz/box_maker_path_to_flex/box_maker_path_to_flex.inx b/extensions/fablabchemnitz/box_maker_path_to_flex/box_maker_path_to_flex.inx
index 7f2acae2..480e6082 100644
--- a/extensions/fablabchemnitz/box_maker_path_to_flex/box_maker_path_to_flex.inx
+++ b/extensions/fablabchemnitz/box_maker_path_to_flex/box_maker_path_to_flex.inx
@@ -5,11 +5,7 @@
     <param name="unit" type="optiongroup" appearance="combo" gui-text="Unit">
         <option value="mm">mm</option>
         <option value="cm">cm</option>
-        <option value="m">m</option>
-        <option value="km">km</option>
         <option value="in">in</option>
-        <option value="ft">ft</option>
-        <option value="yd">yd</option>
         <option value="pt">pt</option>
         <option value="px">px</option>
         <option value="pc">pc</option>
diff --git a/extensions/fablabchemnitz/collar/collar.inx b/extensions/fablabchemnitz/collar/collar.inx
index 36606465..94027736 100644
--- a/extensions/fablabchemnitz/collar/collar.inx
+++ b/extensions/fablabchemnitz/collar/collar.inx
@@ -16,13 +16,10 @@
             <param name="unit" type="optiongroup" appearance="combo" gui-text="Dimensional units:">
                 <option value="mm">mm</option>
                 <option value="cm">cm</option>
-                <option value="m">m</option>
-                <option value="km">km</option>
                 <option value="px">px</option>
                 <option value="pt">pt</option>
+                <option value="pc">pc</option>
                 <option value="in">in</option>
-                <option value="ft">ft</option>
-                <option value="yd">yd</option>
             </param>
             <label appearance="header">Styles</label>
             <param name="generate_decorative_wrapper" type="bool" gui-text="Generate decorative wrapper">false</param>
diff --git a/extensions/fablabchemnitz/dimensioning/dimensioning.inx b/extensions/fablabchemnitz/dimensioning/dimensioning.inx
index 2c2efde9..30907710 100644
--- a/extensions/fablabchemnitz/dimensioning/dimensioning.inx
+++ b/extensions/fablabchemnitz/dimensioning/dimensioning.inx
@@ -27,7 +27,6 @@
             <option value="pt">pt</option>
             <option value="mm">mm</option>
             <option value="cm">cm</option>
-            <option value="m">m</option>
          </param>
          <param name="digit" type="int" min="-3" max="5" gui-text="Precision">0</param>
          <!--
diff --git a/extensions/fablabchemnitz/extruder/extruder.inx b/extensions/fablabchemnitz/extruder/extruder.inx
index 3c6d5102..46791943 100644
--- a/extensions/fablabchemnitz/extruder/extruder.inx
+++ b/extensions/fablabchemnitz/extruder/extruder.inx
@@ -13,13 +13,10 @@
             <param name="unit" type="optiongroup" appearance="combo" gui-text="Dimensional units:">
                 <option value="mm">mm</option>
                 <option value="cm">cm</option>
-                <option value="m">m</option>
-                <option value="km">km</option>
                 <option value="px">px</option>
                 <option value="pt">pt</option>
+                <option value="pc">pc</option>
                 <option value="in">in</option>
-                <option value="ft">ft</option>
-                <option value="yd">yd</option>
             </param>
             <label appearance="header">Styles</label>
             <param name="generate_decorative_wrapper" type="bool" gui-text="Generate decorative wrapper">false</param>
diff --git a/extensions/fablabchemnitz/filter_by_length_area/filter_by_length_area.inx b/extensions/fablabchemnitz/filter_by_length_area/filter_by_length_area.inx
index 9a54b471..7d7d39a2 100644
--- a/extensions/fablabchemnitz/filter_by_length_area/filter_by_length_area.inx
+++ b/extensions/fablabchemnitz/filter_by_length_area/filter_by_length_area.inx
@@ -6,7 +6,10 @@
     <param name="unit" gui-text="Unit" type="optiongroup" appearance="combo">
         <option value="mm">mm</option>
         <option value="cm">cm</option>
-        <option value="m">m</option>
+        <option value="px">px</option>
+        <option value="pt">pt</option>
+        <option value="pc">pc</option>
+        <option value="in">in</option>
     </param>
     <label appearance="header">Threshold</label>
     <param name="min_filter_enable" type="bool" gui-text="Enable filtering min.">false</param>
diff --git a/extensions/fablabchemnitz/parallel_translation/parallel_translation.inx b/extensions/fablabchemnitz/parallel_translation/parallel_translation.inx
index fd89cc13..9431aad8 100644
--- a/extensions/fablabchemnitz/parallel_translation/parallel_translation.inx
+++ b/extensions/fablabchemnitz/parallel_translation/parallel_translation.inx
@@ -31,12 +31,7 @@ Alignment groups shall contain an object to mark its 'rotation center'. The exte
                     <option value="in">in</option>
                     <option value="mm">mm</option>
                     <option value="cm">cm</option>
-                    <option value="m">m</option>
-                    <option value="km">km</option>
-                    <option value="Q">Q</option>
                     <option value="pc">pc</option>
-                    <option value="yd">yd</option>
-                    <option value="ft">ft</option>
                 </param>
             </hbox>
             <param name="reverse" type="bool" gui-text="Translate in opposite direction">false</param>
@@ -74,12 +69,7 @@ Alignment groups shall contain an object to mark its 'rotation center'. The exte
                     <option value="in">in</option>
                     <option value="mm">mm</option>
                     <option value="cm">cm</option>
-                    <option value="m">m</option>
-                    <option value="km">km</option>
-                    <option value="Q">Q</option>
                     <option value="pc">pc</option>
-                    <option value="yd">yd</option>
-                    <option value="ft">ft</option>
                 </param>
             </hbox>
             <param name="reverseG" type="bool" gui-text="Rotate group by an additional angle of 180 degrees" gui-description="This may be handy in case the start- and end-node of the controlling path segment are reversed.">false</param>
diff --git a/extensions/fablabchemnitz/polygen/polygen.inx b/extensions/fablabchemnitz/polygen/polygen.inx
index a6814ba1..74e2fbe1 100644
--- a/extensions/fablabchemnitz/polygen/polygen.inx
+++ b/extensions/fablabchemnitz/polygen/polygen.inx
@@ -12,13 +12,10 @@
         <param name="unit" type="optiongroup" appearance="combo" gui-text="Dimensional units of above parameters and the selected paths:">
             <option value="mm">mm</option>
             <option value="cm">cm</option>
-            <option value="m">m</option>
-            <option value="km">km</option>
             <option value="px">px</option>
             <option value="pt">pt</option>
+            <option value="pc">pc</option>
             <option value="in">in</option>
-            <option value="ft">ft</option>
-            <option value="yd">yd</option>
         </param>
             <label appearance="header">Styles</label>
             <param name="generate_decorative_wrapper" type="bool" gui-text="Generate decorative wrapper">false</param>
diff --git a/extensions/fablabchemnitz/polyhedra/polyhedra.inx b/extensions/fablabchemnitz/polyhedra/polyhedra.inx
index c094a39b..4acbb083 100644
--- a/extensions/fablabchemnitz/polyhedra/polyhedra.inx
+++ b/extensions/fablabchemnitz/polyhedra/polyhedra.inx
@@ -41,7 +41,6 @@
     <param name="unit" type="optiongroup" appearance="combo" gui-text="Units">
         <option value="mm">mm</option>
         <option value="cm">cm</option>
-        <option value="m">m</option>
         <option value="in">in</option>
         <option value="pt">pt</option>
         <option value="px">px</option>
diff --git a/extensions/fablabchemnitz/raytracing/lens.inx b/extensions/fablabchemnitz/raytracing/lens.inx
index 49227e93..b5f5ca03 100644
--- a/extensions/fablabchemnitz/raytracing/lens.inx
+++ b/extensions/fablabchemnitz/raytracing/lens.inx
@@ -6,7 +6,6 @@
     <param name="focal_length_unit" type="optiongroup" appearance="combo" gui-text=" ">
         <option value="mm">mm</option>
         <option value="cm">cm</option>
-        <option value="m">m</option>
         <option value="in">in</option>
     </param>
     <param name="diameter" type="float" gui-text="Diameter:" min="0" max="10000" precision="3">1</param>
@@ -14,14 +13,12 @@
         <option value="in">in</option>
         <option value="mm">mm</option>
         <option value="cm">cm</option>
-        <option value="m">m</option>
     </param>
     <param name="edge_thickness" type="float" gui-text="Edge thickness:" min="0" max="10000" precision="3">2</param>
     <param name="edge_thickness_unit" type="optiongroup" appearance="combo" gui-text=" ">
         <option value="mm">mm</option>
         <option value="in">in</option>
         <option value="cm">cm</option>
-        <option value="m">m</option>
     </param>
     <param name="optical_index" type="float" min="1." max="3." precision="4" gui-text="Optical index:">1.5168</param>
     <param name="lens_type" type="optiongroup" appearance="combo" gui-text="Lens type:">
diff --git a/extensions/fablabchemnitz/robot_boxes/robot_boxes.inx b/extensions/fablabchemnitz/robot_boxes/robot_boxes.inx
index d2a1aefd..c6c50c7e 100644
--- a/extensions/fablabchemnitz/robot_boxes/robot_boxes.inx
+++ b/extensions/fablabchemnitz/robot_boxes/robot_boxes.inx
@@ -16,9 +16,7 @@
     </param>
     <param name="unit" type="optiongroup" appearance="combo" gui-text="Unit">
         <option value="cm">cm</option>
-        <option value="ft">ft</option>
         <option value="in">in</option>
-        <option value="m">m</option>
         <option value="mm">mm</option>
         <option value="pc">pc</option>
         <option value="pt">pt</option>
diff --git a/extensions/fablabchemnitz/scale_to_real/scale_to_real.inx b/extensions/fablabchemnitz/scale_to_real/scale_to_real.inx
index b505d135..0f36bc41 100644
--- a/extensions/fablabchemnitz/scale_to_real/scale_to_real.inx
+++ b/extensions/fablabchemnitz/scale_to_real/scale_to_real.inx
@@ -8,14 +8,11 @@
          <param name="length" type="float" min="0.1" max="100000.0" precision="3" gui-text="Length of scaling path:" gui-description="Real-world length of the scaling path">100.0</param>
          <param name="unit" type="optiongroup" appearance="combo" gui-text="Unit: " gui-description="Real-world unit for drawing">
             <option value="px">px</option>
+            <option value="pc">pc</option>
             <option value="pt">pt</option>
             <option value="in">in</option>
-            <option value="ft">ft</option>
-            <option value="yd">yd</option>
             <option value="mm">mm</option>
             <option value="cm">cm</option>
-            <option value="m">m</option>
-            <option value="km">km</option>
          </param>
          <label appearance="header">Scale Drawing</label>
          <param name="choosescale" gui-text="Scale Category"  gui-description="Select which kind of scaling you would like to use, then select the actual scale in the corresponding dropdown." type="optiongroup" appearance="combo">
diff --git a/extensions/fablabchemnitz/scale_to_size/scale_to_size.inx b/extensions/fablabchemnitz/scale_to_size/scale_to_size.inx
index b3baf2df..b6820013 100644
--- a/extensions/fablabchemnitz/scale_to_size/scale_to_size.inx
+++ b/extensions/fablabchemnitz/scale_to_size/scale_to_size.inx
@@ -5,7 +5,6 @@
     <param name="unit" gui-text="Unit" type="optiongroup" appearance="combo">
         <option value="mm">mm</option>
         <option value="cm">cm</option>
-        <option value="m">m</option>
         <option value="in">in</option>
         <option value="pt">pt</option>
         <option value="px">px</option>
diff --git a/extensions/fablabchemnitz/split_and_break_bezier_at_t/split_and_break_bezier_at_t.inx b/extensions/fablabchemnitz/split_and_break_bezier_at_t/split_and_break_bezier_at_t.inx
index 7cfcf9e3..6c2c3866 100644
--- a/extensions/fablabchemnitz/split_and_break_bezier_at_t/split_and_break_bezier_at_t.inx
+++ b/extensions/fablabchemnitz/split_and_break_bezier_at_t/split_and_break_bezier_at_t.inx
@@ -11,7 +11,6 @@
             <param name="unit" type="optiongroup" appearance="combo" gui-text="Units">
                 <option value="mm">mm</option>
                 <option value="cm">cm</option>
-                <option value="m">m</option>
                 <option value="in">in</option>
                 <option value="pt">pt</option>
                 <option value="px">px</option>
diff --git a/extensions/fablabchemnitz/tab_generator/tab_generator.inx b/extensions/fablabchemnitz/tab_generator/tab_generator.inx
index c95fbcf7..9252a688 100644
--- a/extensions/fablabchemnitz/tab_generator/tab_generator.inx
+++ b/extensions/fablabchemnitz/tab_generator/tab_generator.inx
@@ -16,13 +16,10 @@
             <param name="unit" type="optiongroup" appearance="combo" gui-text="Dimensional units of above parameters and the selected paths:">
                 <option value="mm">mm</option>
                 <option value="cm">cm</option>
-                <option value="m">m</option>
-                <option value="km">km</option>
                 <option value="px">px</option>
                 <option value="pt">pt</option>
+                <option value="pc">pc</option>
                 <option value="in">in</option>
-                <option value="ft">ft</option>
-                <option value="yd">yd</option>
             </param>
             <label appearance="header">Styles</label>
             <param name="cosmetic_dash_style" type="bool" gui-text="Cosmetic dash lines" gui-description="If entered dash line length is zero we can apply some cosmetic style only">false</param>
diff --git a/extensions/fablabchemnitz/triangle/meta.json b/extensions/fablabchemnitz/triangle/meta.json
new file mode 100644
index 00000000..b475d58c
--- /dev/null
+++ b/extensions/fablabchemnitz/triangle/meta.json
@@ -0,0 +1,20 @@
+[
+  {
+    "name": "Triangle",
+    "id": "fablabchemnitz.de.triangle",
+    "path": "triangle",
+    "original_name": "Triangle",
+    "original_id": "math.triangle",
+    "license": "GNU GPL v2",
+    "license_url": "https://gitlab.com/inkscape/extensions/-/blob/master/LICENSE.txt",
+    "comment": "",
+    "source_url": "https://gitea.fablabchemnitz.de/FabLab_Chemnitz/mightyscape-1.X/src/branch/master/extensions/fablabchemnitz/triangle",
+    "fork_url": "https://gitlab.com/inkscape/extensions/",
+    "documentation_url": "https://stadtfabrikanten.org/display/IFM/Triangle",
+    "inkscape_gallery_url": null,
+    "main_authors": [
+      "John Beard:john.j.beard@gmail.com",
+      "github.com/vmario89"
+    ]
+  }
+]
\ No newline at end of file
diff --git a/extensions/fablabchemnitz/triangle/triangle.inx b/extensions/fablabchemnitz/triangle/triangle.inx
new file mode 100644
index 00000000..fe6df168
--- /dev/null
+++ b/extensions/fablabchemnitz/triangle/triangle.inx
@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<inkscape-extension xmlns="http://www.inkscape.org/namespace/inkscape/extension">
+    <name>Triangle</name>
+    <id>fablabchemnitz.de.triangle</id>
+    <param name="unit" type="optiongroup" appearance="combo" gui-text="Units:">
+        <option value="mm">mm</option>
+        <option value="cm">cm</option>
+        <option value="px">px</option>
+        <option value="pt">pt</option>
+        <option value="pc">pc</option>
+        <option value="in">in</option>
+    </param>
+    <param name="s_a" type="float" min="0.01" max="10000" gui-text="Side Length a:">100.0</param>
+    <param name="s_b" type="float" min="0.01" max="10000" gui-text="Side Length b:">100.0</param>
+    <param name="s_c" type="float" min="0.01" max="10000" gui-text="Side Length c:">100.0</param>
+    <param name="a_a" type="float" min="0" max="180" gui-text="Angle a (deg):">60</param>
+    <param name="a_b" type="float" min="0" max="180" gui-text="Angle b (deg):">30</param>
+    <param name="a_c" type="float" min="0" max="180" gui-text="Angle c (deg):">90</param>
+    <param name="mode" type="optiongroup" appearance="combo" gui-text="Mode:">
+        <option value="3_sides">From Three Sides</option>
+        <option value="s_ab_a_c">From Sides a, b and Angle c</option>
+        <option value="s_ab_a_a">From Sides a, b and Angle a</option>
+        <option value="s_a_a_ab">From Side a and Angles a, b</option>
+        <option value="s_c_a_ab">From Side c and Angles a, b</option>
+    </param>
+    <effect>
+        <object-type>all</object-type>
+        <effects-menu>
+            <submenu name="FabLab Chemnitz">
+                <submenu name="Shape/Pattern from Generator" />
+            </submenu>
+        </effects-menu>
+    </effect>
+    <script>
+        <command location="inx" interpreter="python">triangle.py</command>
+    </script>
+</inkscape-extension>
\ No newline at end of file
diff --git a/extensions/fablabchemnitz/triangle/triangle.py b/extensions/fablabchemnitz/triangle/triangle.py
new file mode 100644
index 00000000..bc3f237e
--- /dev/null
+++ b/extensions/fablabchemnitz/triangle/triangle.py
@@ -0,0 +1,188 @@
+#! /usr/bin/python3
+#
+# Copyright (C) 2007 John Beard john.j.beard@gmail.com
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+"""
+This extension allows you to draw a triangle given certain information
+ about side length or angles.
+
+Measurements of the triangle
+
+         C(x_c,y_c)
+        /`__
+       / a_c``--__
+      /           ``--__ s_a
+ s_b /                  ``--__
+    /a_a                    a_b`--__
+   /--------------------------------``B(x_b, y_b)
+  A(x_a,y_a)         s_b
+"""
+
+import sys
+from math import acos, asin, cos, pi, sin, sqrt
+
+import inkex
+
+X, Y = range(2)
+
+def draw_SVG_tri(point1, point2, point3, offset, width, name, parent):
+    style = {'stroke': '#000000', 'stroke-width': str(width), 'fill': 'none'}
+    elem = parent.add(inkex.PathElement())
+    elem.update(**{
+        'style': style,
+        'inkscape:label': name,
+         'd': 'M ' + str(point1[X] + offset[X]) + ',' + str(point1[Y] + offset[Y]) +
+              ' L ' + str(point2[X] + offset[X]) + ',' + str(point2[Y] + offset[Y]) +
+              ' L ' + str(point3[X] + offset[X]) + ',' + str(point3[Y] + offset[Y]) +
+              ' L ' + str(point1[X] + offset[X]) + ',' + str(point1[Y] + offset[Y]) + ' z'})
+    return elem
+
+
+def angle_from_3_sides(a, b, c):  # return the angle opposite side c
+    cosx = (a * a + b * b - c * c) / (2 * a * b)  # use the cosine rule
+    return acos(cosx)
+
+
+def third_side_from_enclosed_angle(s_a, s_b, a_c):  # return the side opposite a_c
+    c_squared = s_a * s_a + s_b * s_b - 2 * s_a * s_b * cos(a_c)
+    if c_squared > 0:
+        return sqrt(c_squared)
+    else:
+        return 0  # means we have an invalid or degenerate triangle (zero is caught at the drawing stage)
+
+
+def pt_on_circ(radius, angle):  # return the x,y coordinate of the polar coordinate
+    x = radius * cos(angle)
+    y = radius * sin(angle)
+    return [x, y]
+
+
+def v_add(point1, point2):  # add an offset to coordinates
+    return [point1[X] + point2[X], point1[Y] + point2[Y]]
+
+
+def is_valid_tri_from_sides(a, b, c):  # check whether triangle with sides a,b,c is valid
+    return (a + b) > c and (a + c) > b and (b + c) > a and a > 0 and b > 0 and c > 0  # two sides must always be greater than the third
+    # no zero-length sides, no degenerate case
+
+
+def draw_tri_from_3_sides(s_a, s_b, s_c, offset, width, parent):  # draw a triangle from three sides (with a given offset
+    if is_valid_tri_from_sides(s_a, s_b, s_c):
+        a_b = angle_from_3_sides(s_a, s_c, s_b)
+
+        a = (0, 0)  # a is the origin
+        b = v_add(a, (s_c, 0))  # point B is horizontal from the origin
+        c = v_add(b, pt_on_circ(s_a, pi - a_b))  # get point c
+        c[1] = -c[1]
+
+        offx = max(b[0], c[0]) / 2  # b or c could be the furthest right
+        offy = c[1] / 2  # c is the highest point
+        offset = (offset[0] - offx, offset[1] - offy)  # add the centre of the triangle to the offset
+
+        draw_SVG_tri(a, b, c, offset, width, 'Triangle', parent)
+    else:
+        inkex.errormsg('Invalid Triangle Specifications.')
+
+
+class Triangle(inkex.EffectExtension):
+    def add_arguments(self, pars):
+        pars.add_argument("--unit", default="mm", help="Units")
+        pars.add_argument("--s_a", type=float, default=100.0, help="Side Length a")
+        pars.add_argument("--s_b", type=float, default=100.0, help="Side Length b")
+        pars.add_argument("--s_c", type=float, default=100.0, help="Side Length c")
+        pars.add_argument("--a_a", type=float, default=60.0, help="Angle a")
+        pars.add_argument("--a_b", type=float, default=30.0, help="Angle b")
+        pars.add_argument("--a_c", type=float, default=90.0, help="Angle c")
+        pars.add_argument("--mode", default='3_sides', help="Side Length c")
+
+    def effect(self):
+        tri = self.svg.get_current_layer()
+        offset = self.svg.namedview.center
+        self.options.s_a = self.svg.unittouu(str(self.options.s_a) + self.options.unit)
+        self.options.s_b = self.svg.unittouu(str(self.options.s_b) + self.options.unit)
+        self.options.s_c = self.svg.unittouu(str(self.options.s_c) + self.options.unit)
+        stroke_width = self.svg.unittouu('1px')
+
+        if self.options.mode == '3_sides':
+            s_a = self.options.s_a
+            s_b = self.options.s_b
+            s_c = self.options.s_c
+            draw_tri_from_3_sides(s_a, s_b, s_c, offset, stroke_width, tri)
+
+        elif self.options.mode == 's_ab_a_c':
+            s_a = self.options.s_a
+            s_b = self.options.s_b
+            a_c = self.options.a_c * pi / 180  # in rad
+
+            s_c = third_side_from_enclosed_angle(s_a, s_b, a_c)
+            draw_tri_from_3_sides(s_a, s_b, s_c, offset, stroke_width, tri)
+
+        elif self.options.mode == 's_ab_a_a':
+            s_a = self.options.s_a
+            s_b = self.options.s_b
+            a_a = self.options.a_a * pi / 180  # in rad
+
+            if (a_a < pi / 2.0) and (s_a < s_b) and (s_a > s_b * sin(a_a)):  # this is an ambiguous case
+                ambiguous = True  # we will give both answers
+            else:
+                ambiguous = False
+
+            sin_a_b = s_b * sin(a_a) / s_a
+
+            if (sin_a_b <= 1) and (sin_a_b >= -1):  # check the solution is possible
+                a_b = asin(sin_a_b)  # acute solution
+                a_c = pi - a_a - a_b
+                error = False
+            else:
+                sys.stderr.write('Error:Invalid Triangle Specifications.\n')  # signal an error
+                error = True
+
+            if not error and (a_b < pi) and (a_c < pi):  # check that the solution is valid, if so draw acute solution
+                s_c = third_side_from_enclosed_angle(s_a, s_b, a_c)
+                draw_tri_from_3_sides(s_a, s_b, s_c, offset, stroke_width, tri)
+
+            if not error and ((a_b > pi) or (a_c > pi) or ambiguous):  # we want the obtuse solution
+                a_b = pi - a_b
+                a_c = pi - a_a - a_b
+                s_c = third_side_from_enclosed_angle(s_a, s_b, a_c)
+                draw_tri_from_3_sides(s_a, s_b, s_c, offset, stroke_width, tri)
+
+        elif self.options.mode == 's_a_a_ab':
+            s_a = self.options.s_a
+            a_a = self.options.a_a * pi / 180  # in rad
+            a_b = self.options.a_b * pi / 180  # in rad
+
+            a_c = pi - a_a - a_b
+            s_b = s_a * sin(a_b) / sin(a_a)
+            s_c = s_a * sin(a_c) / sin(a_a)
+
+            draw_tri_from_3_sides(s_a, s_b, s_c, offset, stroke_width, tri)
+
+        elif self.options.mode == 's_c_a_ab':
+            s_c = self.options.s_c
+            a_a = self.options.a_a * pi / 180  # in rad
+            a_b = self.options.a_b * pi / 180  # in rad
+
+            a_c = pi - a_a - a_b
+            s_a = s_c * sin(a_a) / sin(a_c)
+            s_b = s_c * sin(a_b) / sin(a_c)
+
+            draw_tri_from_3_sides(s_a, s_b, s_c, offset, stroke_width, tri)
+
+
+if __name__ == '__main__':
+    Triangle().run()
diff --git a/extensions/fablabchemnitz/unwind_paths/unwind_paths.inx b/extensions/fablabchemnitz/unwind_paths/unwind_paths.inx
index e698177e..aaa05a4e 100644
--- a/extensions/fablabchemnitz/unwind_paths/unwind_paths.inx
+++ b/extensions/fablabchemnitz/unwind_paths/unwind_paths.inx
@@ -18,7 +18,6 @@
             <param name="unit" gui-text="Unit" type="optiongroup" appearance="combo">
                 <option value="mm">mm</option>
                 <option value="cm">cm</option>
-                <option value="m">m</option>
                 <option value="in">in</option>
                 <option value="pt">pt</option>
                 <option value="px">px</option>