polyhedron(
  points=[ 
    [10,10,0],
    [10,-10,0],
    [-10,-10,0],
    [-10,10,0],
    [0,0,10]  
  ],
  triangles=[ 
    [0,1,4],
    [1,2,4],
    [2,3,4],
    [3,0,4],
    [1,0,3],
    [2,1,3] 
  ]
 );