1. 9-2A Volume of Prisms What is volume?
What question must you ask before you can begin finding the volume of a prism?

2. Definition
His mom yelled at him to turn the volume down on his playstation.
The volume of the bottle was two liters.
The volume of a solid is the number of cubic units contained in the solid.
Volume measures how much a solid can “hold”.

3. Count Up the Volume Find the volume of the right rectangular prism.
Write a formula for finding the volume of a right rectangular prism.
What is the area of a rectangle?
How does the shape of the base work into the volume formula? l w H
V = l · w · H

4. Find the Volume Ask: What is the shape of the base? V = l w H

5. Find the Volume What is the shape of the base? V = ½ b h H
V = 42,398 mm3
68 mm
43 mm
29 mm

6. Cavalieri’s Principle
Turn to page 626 in your book.
Cavalieri’s principle states that if two prisms have the same base area and the same height, then they will have the same volume.
That means whether you have a right prism or an oblique prism, the volume will be the same.

7. Theorem
The volume of a right rectangular prism is the product of its length, width, and height.
V = l w H H w l

8. Theorem
The volume of any prism is the product of the area of its base and its height.
V = b H
We will be working with prisms with square, rectangular and triangular bases.
Ask: What is the shape of the base?

9. Assignment 9-2A NO FORMULAS WITH NUMBERS NO CREDIT
Page 628, 11-12, 27-28
and worksheet
NO FORMULAS WITH NUMBERS
NO CREDIT