2. polyhedron a three- dimensional figure whose surfaces are polygons faces edge vertex

3. Euler’s Formula The number of faces (F), vertices (V), and edges (E) of a polyhedron three- dimensional are related by the formula F + V = E + 2

4. Example A polyhedron has 8 faces and 18 edges. How many vertices does this polyhedron have ? F + V = E + 2 8 + V = 18 + 2 8 + V = 20 -8 -8 V = 12

5. Euler’s Formula The number of faces (F), vertices (V), and edges (E) of a polyhedron in two- dimensional are related by the formula F + V = E + 1

6. How many regions, vertices and segments are on the following polyhedron in 2- dimension space ? regions 1 23 4 56 7 8 8 segments 1 2 3 4 5 6 7 8 9 10111213 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

7. How many regions, vertices and segments are on the following polyhedron in 2- dimension space ? regions 8 segments 1 2 3 4 5 6 7 8 9 1011 12 13 14 15 16 17 18192021 22 29 vertices

8. Cross sections Slicing the polyhedron with a plane and examining the resulting figure.

10. Assignment Workbook Page 463 all