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Polyhedrons. An introduction to 3D Figures. What is a polyhedron?. 3 Dimensional figure Formed by polygons Takes up space. Parts of a polyhedron. Face: The flat polygonal surfaces “sides” Edge Where the faces meet Line segments Vertex Point of intersection of three or more edges
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Polyhedrons An introduction to 3D Figures
What is a polyhedron? • 3 Dimensional figure • Formed by polygons • Takes up space
Parts of a polyhedron • Face: • The flat polygonal surfaces • “sides” • Edge • Where the faces meet • Line segments • Vertex • Point of intersection of three or more edges • Where line segments meet
Prisms • Has two bases • Polygons • Congruent • Parallel • Faces • Connect the bases • Height is the altitude (perpendicular distance between the bases) • Right Prisms • Faces are perpendicular to the bases • Height=altitude= perpendicular distance • Oblique Prisms • Faces are NOT perpendicular
Pyramids • Only one base • Base determines type of pyramid • Has faces that meet at a common vertexes • Faces are always triangles
Practice Identify the figure. Name the bases. Name the lateral faces. Name the edges. Name an altitude.
Practice Identify the figure. Name the bases. Name the lateral faces. Name the edges. Name an altitude.
Practice Identify the figure. Name the bases. Name the lateral faces. Name the edges. Name an altitude.
Curved Surface Solids An Introduction to Cylinders, Cones, and Spheres
Cylinder Define Parts Axis (Altitude) Radius • Bases • Congruent • Parallel • Circles • If line connecting the bases is perpendicular to the bases, then it is a right cylinder, if not, its oblique.
Cone Define Parts Apex Radius Altitude Base • Has one circular base • Lateral surface meets at a vertex called an apex • Right Cone: when line from apex to base is perpendicular to the base • Oblique Cone: Not perpendicular. Height is still the altitude.
Sphere Define: Parts Center Radius Hemisphere Great Circle • A set of all points from a given point in space. • How is that different from a circle?