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Polyhedrons: Prisms. Tutorial 5b. 3D Solids. To review polygons –see tutorial 5a. faces. •. •. A polyhedron is a 3-dimensional figure whose surfaces are polygons. •. •. The polygons are the faces of the polyhedron. edge.
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Polyhedrons: Prisms Tutorial 5b
3D Solids To review polygons –see tutorial 5a. faces • • • A polyhedron is a 3-dimensional figure whose surfaces are polygons. • • • The polygons are the faces of the polyhedron. edge • An edge is a segment that is the intersection of two faces. • • • • A vertex is a point where edges intersect. vertex
Figures • Identify a face, an edge, and a vertex on this polyhedron. Hexagon ABCDEF Rectangle IFEH Rectangle EHGD Faces: A B Edges: Segments AB, BC,CD, DE, EF, FA, IF, HE, GD F C I E D Vertices: Points A, B, C, D, E, F, G, H, I H G
Prisms: • A prism is a polyhedron with two congruent & parallelbases. • The other faces are the lateral faces. • A prism is named for the shape of its bases. Rectangular Prism: lateral edge bases lateral faces
Prisms cont. . . • An altitude of a prism is a perpendicular segment that joins the planes of the bases. • The heighth 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. Oblique prism Right prisms h h h
A net: When folded it forms: Three-dimensional Two-dimensional 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.
Nets • What three-dimensional shape does this net create? A pyramid
The End Time to move on to the assignment or the next lesson