Polyhedra Mikhаilichenko Yelena-Maths teacher Tsoy Svetlana- English teacher
Polyhedron is a geometric body which consists of a finite number of intersecting planes
Prism is a polyhedron consisting of two parallel polygons, basing on finite numbers of rectangles which form a side surface. V=SH
Pyramid is a geometric body which consists of some triangles with common vertex and the base. V=1/3 SH
Cube is a prism with equal faces. V= a³ ,where a is an edge.
Regular Polyhedra
Non of the geometric body does not possess such beauty as regular polyhedra. There are 5 types of polyhedra: tetrahedron, cube, octahedron, dodehedron and icosahedron.
The Euler characteristic The number of faces F The number of vertices V The number of edges E Regular polyhedron F+V-E=24 4 6 tetrahedron 2 8 12 cube octahedron 20 30 dodecahedron icosahedron
Regular Polyhedra in nature