1. 1-7 Three-Dimensional Figures What is a polyhedron? How are polyhedrons classified? What are Platonic solids?

2. You identified and named two-dimensional figures. Identify and name three-dimensional figures.

3. Definitions A polyhedron is a solid with all flat surfaces that enclose a single region of space. A face is each flat surface of the polygon Faces are named in the same way as polygons. Edges are the line segments where the faces intersect. A vertex is the point where three or more edges meet. Polyhedrons or polyhedra are named by the shape of their bases and type of solid.

4. p. 67

5.  Prisms and pyramids are Polyhedrons.  Cylinders, cones and spheres are not.

6. Bases TTTThe bases of the figure are the two parallel congruent faces of the three dimensional figure. BBBBEWARE!! TTTThe figure may not be sitting on its base

7. Naming polyhedrons  Polyhedrons are named by the shape of their bases.

8. Identify Solids Determine whether the solid is a polyhedron. Then identify the solid. If it is a polyhedron, name the bases, faces, edges, and vertices. The solid is formed by polygonal faces, so it is a polyhedron. The bases are rectangles. This solid is a rectangular prism. Answer: rectangular prism Bases:rectangles EFHG, ABDC Faces:rectangles FBDH, EACG, GCDH,EFBA, EFHG, ABDC Vertices:A, B, C, D, E, F, G, H

9. Identify Solids Determine whether the solid is a polyhedron. Then identify the solid. If it is a polyhedron, name the bases, faces, edges, and vertices. The solid has a curved surface, so it is not a polyhedron. The base is a circle and there is one vertex. So, it is a cone. Answer: Base: circle T Vertex: W no faces or edges

10. Identify the solid A.triangular prism B.triangular pyramid C.rectangular pyramid D.cone

11. Platonic Solids

12. Identify the solid A.cone B.cylinder C.pyramid D.polyhedron

13. Identify the solid A.triangular pyramid B.pentagonal prism C.rectangular prism D.square pyramid

14.  What is a polyhedron? A polyhedron is a solid whose faces are polygons.  How are polyhedrons classified? Polyhedrons are named by the shape of their bases.

15. Assignment 1-7 Page 70, 1, 2, 6-16, skip 12