Euler's polyhedron formula

The theorem formulated by Leonhard Euler describes one of the basic properties of convex polyhedra.

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Császár polyhedron

The Császár polyhedron is a nonconvex polyhedron with 14 triangular faces.

Volume of spheres (Cavalieri´s principle)

Calculating the volume of a sphere is possible using an appropriate cylinder and cone.

Geometric transformations – translation

This animation demonstrates geometric translation in both plane and space.

Weighing the Pythagorean theorem

In this experiment we provide proof of the well-known theorem of Pythagoras with a scale.

Non-orientable surfaces

The Möbius strip and the Klein bottle are special two-dimensional surfaces with only one...


An entertaining game about different views of spatial objects.

Coloring a cube

Coloring the vertices, edges and faces of a given cube according to the criteria...

How does the volume of a cylinder relate to the volume of a cone?

In this experiment we prove that the volume of a cylinder is three times the volume of a cone.

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