In geometry, the great triakis octahedron is the dual of the stellated truncated hexahedron (U19). It has 24 intersecting isosceles triangle faces. Part of each triangle lies within the solid, hence is invisible in solid models.
The triangles have one angle of
\arccos( | 1 | + |
4 |
1 | |
2 |
\sqrt{2}) ≈ 16.84211623630\circ
\arccos( | 1 | - |
2 |
1 | |
4 |
\sqrt{2}) ≈ 81.57894188185\circ
\arccos( | -3+8\sqrt{2 |