1. 11-1 Space Figures and Cross Sections

2. Polyhedron: a space figure, or three-dimensional figure, whose surfaces are polygons Face: the flat surface of a figure Edge: Formed by the intersection of two faces Vertex: the point where three or more edges intersect
Vertex
Edge
Faces

3. Problem 1: Identifying Vertices, Edges, and Faces
How many vertices, edges, and faces are in the polyhedron? List them.

4. Euler’s Formula
𝐹+𝑉=𝐸+2 F=faces V=vertices E=Edges

5. Problem 2: Using Euler’s Formula
For each polyhedron, use Euler’s Formula to find the missing number

6. For each polyhedron, use Euler’s Formula to find the missing number

7. Problem 4: Describing a Cross Section
Cross Section: the intersection of a solid and a plane (a thin slice of the solid) What is the cross section formed by the plane and the solid below?

8. What is the cross section formed by a horizontal plane
What is the cross section formed by a horizontal plane? What is the cross section formed by a vertical plane?

9. Problem 5: Drawing a Cross Section
Draw a cross section formed by a vertical plane intersecting the front face and right face of the cube. What shape is the cross section?

10. Draw a cross section formed by a horizontal plane intersecting left and right faces of the cube. What shape is the cross section?