Digits, Grade 8, Volume 1, Homework Helper

### 5-3: Volumes of Cylinders

#### Key Concept

Volume of a Cylinder

The volume of a cylinder is the number of unit cubes, or cubic units, needed to fill the cylinder.

If each layer is one unit high, then the height h represents the number of layers. The formula for the volume of a cylinder is the area of the base times the height. The volume of a cylinder is represented by πr 2 h.

#### Part 1

Example Finding Volumes of Cylinders

What is the volume of each cylinder in terms of π?

• a. • b. • c. Solution

• a. table with 3 rows and 2 columns , row1 column 1 , v , column 2 equals pi , r squared , h , row2 column 1 , , column 2 equals pi . open 4 close squared . open 6 close , row3 column 1 , , column 2 equals 96 pi , end table

The volume of the cylinder is 96π cm3.

• b. table with 3 rows and 2 columns , row1 column 1 , v , column 2 equals pi , r squared , h , row2 column 1 , , column 2 equals pi . open 5 close squared . open 5 close , row3 column 1 , , column 2 equals 125 pi , end table

The volume of the cylinder is 125π cm3.

• c. table with 3 rows and 2 columns , row1 column 1 , v , column 2 equals pi , r squared , h , row2 column 1 , , column 2 equals pi . open 6 close squared . open 4 close , row3 column 1 , , column 2 equals 144 pi , end table

The volume of the cylinder is 144π cm3.

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