MathFoundations 18: Geometry – YouTube

MathFoundations 18: Geometry – YouTube. How to begin geometry? What is the correct framework? How to define point, line, circle etc etc?These are some of the issues we will be addressing in this first look at the logical foundations of geometry.This lecture is part of the MathFoundations series, which tries to lay out proper foundations… Continue reading MathFoundations 18: Geometry – YouTube

Platonic Solids

Platonic Solid — from Wolfram MathWorld. The Platonic solids, also called the regular solids or regular polyhedra, are convex polyhedra with equivalent faces composed of congruent convexregular polygons. There are exactly five such solids (Steinhaus 1999, pp. 252-256): the cube, dodecahedron, icosahedron, octahedron, and tetrahedron, as was proved by Euclid in the last proposition of the Elements. The Platonic solids are sometimes also called “cosmic… Continue reading Platonic Solids