HomeSketchesSimple visualisations of mathematical subjects. More sketches — in the Russian version
Unsolved problems4Periodic billiard trajectoryAperiodic tiling Are there many prime numbers? Normal number π
Polyhedra4 Platonic solids Duality of regular polyhedrons Szilassi polyhedron Tetrahedron altitudes
Curves on plane11Cat on a ladderAstroidTimber raftingHypocycloidEllipsis optical propertyParabola optical propertyParabola as an envelopeEllipse as an envelopeHyperbola as an envelopeHyperbola and ellipse perpendicularityParabolic sieve
Vario6 Reutersvärd’s Impossible Triangle Tricky cubeRoom illuminationRotorTwo circles Walking tours