Google Classroom
GeoGebraGeoGebra Classroom

Icosahedron のコピー

Sometimes regular... The vertices of 3 orthogonal congruent rectangles can be connected to make a polyhedron with 20 triangular faces (icosahedron). One of the most wonderful facts of geometry is that if those rectangles have the golden proportion, it's the regular icosahedron - a platonic solid!
More GeoGebra at bit.ly/mh-ggb