Part 4 of 5

Solid geometry extends all that you have learned into three-dimensional space. Here shapes have volume and surface area, and the relationships between them reveal some of the most beautiful patterns in all of mathematics.

In this part you will explore prisms, pyramids, cylinders, cones, and the sphere, learning how to calculate their volumes and surface areas. You will then meet the Platonic solids — the five perfect three-dimensional forms known since antiquity — followed by the Archimedean solids, Catalan solids, and compound polyhedra. Each family of shapes carries its own deep geometric symmetry.

This is where geometry becomes truly three-dimensional, and where the ancient and the modern converge in pure form.