1. PLANE SLICE
Describe the two-dimensional figures that result from slicing three-dimensional figures

2. Table of contents Vocabulary……………………………………………………………..Slide 3
Lesson A…………………………………………………………………Slide 4
Lesson B………………………………………………………………….Slide 11

3. Vocabulary
CROSS-SECTION- THE SHAPE YOU GET WHEN CUTTING STRAIGHT ACROSS AN OBJECT
PARALLEL- LINES IN A PLANE THAT DO NOT MEET
PERPENDICULAR- RELATIONSHIP BETWEEN TWO LINES WHICH MEET AT A RIGHT ANGLE
FACE- FLAT PLANAR SURFACE
EDGE- LINE WHERE TWO SURFACES MEET
VERTEX- CORNER OF AN INTERSECTION
BASE- SIDE OF A PLANE FIGURE OR FACE OF A SOLID
ANGLE- FIGURE FORMED BY TWO RAYS OR LINE SEGMENTS
DIAGONAL- CROSSING FROM ONE CORNER TO ANOTHER
PLANE- FLAT TWO-DIMENSIONAL SURFACE
RECTANGULAR PRISM- A 3D SHAPE THAT HAS 6 FACES, 8 VERTICES, AND 12 EDGES
RIGHT SQUARE PYRAMID- A 3D SHAPE THAT HAS 5 FACES, 5 VERTICES, AND 8 EDGES

4. Lesson A
In this lesson you will learn how to describe the cross sections of a rectangular prism by slicing at different angles.

5. Review 3D 2D Rectangular Prism Plane Meet at 90˚ Infinitely Tall
Six Faces
Infinitely Long 2D

6. Interpreting a Perspective Drawing
Looking at the prism straight on, the top face looks like a parallelogram.
When the top face is straight up, you can see that it is actually a rectangle.

7. The Plane can be perpendicular or parallel.
A Cross Section is the two-dimensional shape you get when you cut a three-dimensional shape with a plane.
The Plane can be perpendicular or parallel.
Perpendicular Planes intersect to form right angles.
Parallel Planes never intersect

8. Cutting a rectangular prism parallel to its base:
The blue part is your Cross Section

9. Cutting a rectangular prism NOT parallel to its base:
The blue part is your Cross Section

10. Cutting a rectangular prism perpendicular to its base:
The blue part is your Cross Section

11. Lesson B
In this lesson you will learn how to describe the cross sections of a right square pyramid by slicing at different angles.

12. Review
Right Square Pyramid
From Lesson A, recall what a plane is and how it relates to cross sections. View slide five for reference.
Vertex
5 Faces

13. Cutting a right pyramid with a plane parallel to its base:
The blue part is your Cross Section

14. Cutting a right square pyramid NOT parallel to its base:
The blue part is your Cross Section
The ends on the quadrilateral are different lengths because the far side is closer to the top vertex.

15. Cutting a right square pyramid with a plane perpendicular to its base containing the vertex:

16. Sources: