1. Warm Up 04.25.12 Week 6

2. Section 12.1 Day 1 I will use the properties of polyhedra. PolyhedronA solid bounded by polygons (faces). EdgeA line segment at the intersection of faces. VertexA point where three or more edges meet.

3. Types of Solids The prism and pyramid are polyhedra, the cone, cylinder, and sphere are not.

4. Which are polyhedrons? Ex 1

5. Regular Polyhedron If all faces are congruent regular polygons. Convex Polyhedron Line segments stay inside the polyhedron.

6. Concave Polyhedron Line segments go ouside the polyhedron.

7. Ex 2 Are the polyhedra convex? Regular?

8. Assign ment: Textbook Page 723, 10 – 24 all. Do 1: How many faces, edges, and vertices?