1. 11.1 Space Figures and Cross Sections
By Brit Caswell

2. A Little Bit of Vocab
A polyhedron is a 3-D figure whose surfaces are all polygons .

3. Name the vertices of this polyhedron.
How many edges are there?
Name each of the five faces.

4. Euler was a super important guy

5. Try it
Faces:
Edges: 30
Vertices: 20
Faces: 20
Edges:
Vertices: 12

6. Euler’s Formula in 2-D
The formula changes in two dimensions: F + V = E + 1
Faces:
Edges:
Vertices?

7. A cross section is the intersection of a solid and a plane.

8. Pg 690 #4
What is the shape of this cross section?

10. Let’s Practice Drawing This…
Draw a cross section formed by a vertical plane and the front and right faces of the cube.
The next slide shows you how!

12. Describe the cross section.
What would the cross section look like if the plane was vertical?

13. Can you find a cross section of a cube that makes a triangle? Explain.

14. Draw and describe a cross section formed by a plane intersecting a cube such that the plane is tilted and intersects the left and right faces of the cube.

15. A solid of revolution is when a plane revolves completely about a line
A solid of revolution is when a plane revolves completely about a line. For example:
Sketch and describe the solid that is formed by the following figures: