
In a recent workshop, students made these solids. Can you think of reasons why I might have grouped the solids in the way I have before taking the pictures?
Here is a proof of Euler's formula in the plane and on a sphere together with projects to explore cases of the formula for a polygon with holes, for the torus and other solids with holes and the. . . .

60 pieces and a challenge. What can you make and how many of the pieces can you use creating skeleton polyhedra?
Toni Beardon has chosen this article introducing a rich area for practical exploration and discovery in 3D geometry

It is known that the area of the largest equilateral triangular section of a cube is 140sq cm. What is the side length of the cube? The distances between the centres of two adjacent faces of. . . .
In this article, we look at solids constructed using symmetries of their faces.