Area of the pentagon formed by the intersections of the consecutive normals at the vertices of the pentagon remains constant

Two Nephroids Meeting Orthogonally on a Circle

Linkage to Draw the Cardioid Tusi couple

Deltoid Astroid

EllipseEpicycloid Evolute

Epitrochoid Logarithmic Spiral Evolute

InvoluteLogarithmic spiral involute

Epicycloid

Ranunculoid

Rotor1

Rotor2

Rotor3

Roulette1

Roulette2

Roulette3

Roulette4

Torus cannibal

Whirls

Paper birdDiagonal inside regular pentagon Folding and unfolding of a cube. Dodecahedron upon unfolding Clifford torus Magic with polyhedraThe soccer ball CatenoidPolyhedral horse

Nice folding and unfolding of figures

Mice problems p> Spirograph