Tag: pentagonal pyramid



The icosahedron has 12 equilateral triangles as faces. It can be split into 3 parts, a pentagonal anti-prism and two pentagonal pyramids. We will start by looking at a pentagonal pyramid. We have already done most of the work earlier. To find ∠ACB, $$\begin{align}\cos \angle …Read the Rest

Finding the Angles of the Truncated Icosahedron

I’ve been interested in various geometric shapes for many years, from the simple cubes, prisms, and pyramids made in middle school, to the geodesic domes used to build houses. I have cut and glued numerous pieces of paper into just about all of the regular …Read the Rest