Ideas of visual mathematical models.

The sum of exterior angles of a convex polygon is 360°.

What’s the sum of squares of first n natural numbers?

Drawing a parabola with a thread according to its geometric definition.

A ball rolling down the slide in a parabolic billiard always makes it to the pocket!

A cardboard model of a dodecahedron — one of the five regular polyhedra.

Three triangular mirrors, some duct tape and a triangle painted in two colors, combined with the theory of reflection groups allow you to demonstrate an interesting model of a classic soccer ball to your friends.

A simple to do demonstration that the number π equals “three and change”.