Solid Geometry · 16 lessons

The volume of a solid comes from cutting it into pieces you can already measure. The surface area comes from unfolding it flat and adding up the faces. Every formula in this topic is built by one of those two moves.

1. 1Cubes, Spheres, Cones and Cylinders
2. 2The Cuboid
3. Shapes and where they sit (11)
4. 3Nets
5. Circles (11)
6. 4Prisms and Cylinders
7. 5Pyramids and Cones
8. 6Spheres
9. 7Drawing Solids on a Dot Grid
10. 8Scaling Area and Volume
11. 9Euler’s Formula for Polyhedra
12. 10Why There Are Exactly Five Platonic Solids
13. 11Archimedes and the Volume of a Sphere
14. Quadrilaterals (11)
15. Polygons (10)
16. Volume and Surface Area (10)
17. 12Surface Area of a Cuboid
18. 13Surface Area of a Cylinder
19. 14The Slant Height of a Cone
20. 15Cones and Spheres
21. 16Combined Volume and Surface Area
22. 3D solids (12)