6 What is a polyhedron? These are polyhedron: Click here for more polyhedronCrystallographicpolyhedraCreate your ownpolyhedronClick here formore polyhedron
7 A polyhedron is: -three dimensional; -a closed figure; -made up of flat surfaces which are polygons.What is a polyhedron?A polyhedron is a three-dimensional solid whose faces are polygons joined at their edges. The word polyhedron is derived from the Greek poly (many) and the Indo-European hedron (seat).
8 All of the faces (sides) of a polyhedron are polygons. The line segments where the faces intersect arecalled edges.The point where more than two faces intersect iscalled a vertex.vertexedgesface
10 More polyhedroninformationEven more Polyhedron:More polyhedron!
11 There are only five regular polyhedra called the Platonic solids. Crystals are real world examples of polyhedra. The salt you sprinkle on your food is a crystal in the shape of a cube.Math is everywhere!A polyhedron is said to be regular if its faces are made up of regular polygons.There are only five regular polyhedra called the Platonic solids.
12 MoreinfoIn mathematics Plato's name is attached to the Platonic solids. In the Timaeus there is a mathematical construction of the elements (earth, fire, air, and water), in which the cube, tetrahedron, octahedron, and icosahedron are given as the shapes of the atoms of earth, fire, air, and water. The fifth Platonic solid, the dodecahedron, is Plato's model for the whole universe.
14 A pyramid . . . -is a polyhedron that has all faces except one intersecting at one point;-has one polygon base;The sides that are not the base and intersectin a single point are triangles.-is named by the shape of its base.Triangular pyramidPentagonal pyramidHexagonal pyramid
16 A prism . . . -is a polyhedron with two congruent faces called bases that are in parallel planes.The faces that are not bases are parallelograms,and are called lateral faces.-is named by the shape of its bases.ECAFBD
18 How in the worlddo they make those?Click herefor moreinformation
19 A solid with a pair of circular bases is called a cylinder. Is a cylinder a polyhedron?
20 A cone has a circular base and a vertex. Is a cone a polyhedron?
21 Complete the table below. letterName of polyhedronNumber of facesNumber of edgesNumber of verticesABCDEFGH
22 Completed table: A 5 9 6 B 4 C 12 8 D 7 15 10 E F 24 16 G H 21 14 letterName of polyhedronNumber of facesNumber of edgesNumber of verticesATriangular prism596BTriangular pyramid4CSquare prism128DPentagonal prism71510EHexagonal pyramidFOctagonal prism2416GRectangular pyramidHSeptagonal prism2114n = # sides on basePyramid / prismn + 1 / n + 22n / 3nn + 1 / 2n
23 What is the relationship between the number of vertices, faces and edges in a polyhedron?letterName of polyhedronNumber of facesNumber of edgesNumber of verticesATriangular prism596BTriangular pyramid4CSquare prism128DPentagonal prism71510EHexagonal pyramidFOctagonal prism2416GRectangular pyramidHSeptagonal prism2114
24 More Euler information What is the relationship between the numberof vertices, faces and edges in a polyhedron?For any convex polyhedron, the number of vertices and faces together is exactly two more than the number of edges.V + F = 2 + EThis is called Euler’s formula.Click here for proofsof Euler’s formulaMore Euler information
25 Nets for many polyhedra Interactive polyhedronMake some polyhedronmodels