Illustration of an oblique view of a hollow cylinder. The portion removed from the center of the cylinder…

Diagram used to prove the theorem: "The opposite faces of a parallelopiped are equal and parallel."

Diagram used to prove the theorem: "The rectangular parallelopipeds which have two dimensions in common…

Diagram used to prove the theorem: "The rectangular parallelopipeds are to each other as the product…

Diagram used to prove the theorem: "The volume of a rectangular parallelopiped is equal to the product…

Illustration of an oblique view of a rectangular solid/prism at 30°.

Illustration of an oblique view of a rectangular solid/prism at 45°.

Illustration of an oblique view of a rectangular solid/prism at 60°.

Illustration of model created by combining non regular geometric solids.

Illustration of stairs; 3-dimensional view of 4 steps. The staircase can be created by combining/stacking…

Diagram used to prove the theorem: "The plane passed through two diagonally opposite edges of a parallelopiped…