This structure has 12 pentagonal holes. It is built from a Rhombicosidodecahedron, whose pentagons are replaced by pentagonal antiprisms. On top of each antiprism, a square and triangle cupola is added and joined to the others by means of squares and hexagons (or 6 triangles as in this case). You will need a total of 200 eq. triangles, 120 squares and 20 hexagons or 320 equilateral triangles & 120 squares.