Polyhedrons: Prisms Tutorial 5b

3D Solids §A polyhedron is a 3- dimensional figure whose surfaces are polygons. faces edge vertex §The polygons are the faces of the polyhedron. §An edge is a segment that is the intersection of two faces. §A vertex is a point where edges intersect. To review polygons –see tutorial 5a.

Figures §Identify a face, an edge, and a vertex on this polyhedron. A B C D G H E F I Faces: Hexagon ABCDEF Rectangle IFEH Rectangle EHGD Edges: Segments AB, BC,CD, DE, EF, FA, IF, HE, GD Vertices: Points A, B, C, D, E, F, G, H, I

Prisms: §A prism is a polyhedron with two congruent & parallel bases. §The other faces are the lateral faces. §A prism is named for the shape of its bases. Rectangular Prism: baseslateral faces lateral edge

Prisms cont... §An altitude of a prism is a perpendicular segment that joins the planes of the bases. §The height h of the prism is the length of an altitude. §A prism may either be right or oblique. §In a right prism the lateral faces are rectangles and a lateral edge is an altitude. h Right prisms Oblique prism h h

Nets §When a polyhedron is unfolded, the result is a two-dimensional figure called a net. §A net is a two-dimensional pattern that you can fold to form a three-dimensional figure. A net: Two-dimensional When folded it forms: Three-dimensional

Nets §What three-dimensional shape does this net create? A pyramid