1. Volume of Prisms & Cylinders

2. Definitions
A prism is a three-dimensional figure named for the shape of its bases. The two bases are congruent polygons. All of the other faces are parallelograms.

3. Every prism is named by its BASE.
Triangular prism
Height
Base

4. If all six faces of a rectangular prism are squares, it is a cube.
Remember!

5. Definition of a Cylinder
A cylinder is made up of two identical circular bases and one rectangle.

6. Definition of a Cylinder continued…
The BASE of a cylinder is the circle at the top or at the bottom.
Height
The HEIGHT is the distance between the two circular bases.
Base

7. How to Find Volume
Volume of all prisms and cylinders is found by multiplying the area of the base times the height.
Step 1: Decide what shape the base is. (rectangle, triangle or circle)
Step 2: Find the area of the base.
Step 3: Multiply by height.

8. Find the volume of the rectangular prism
Step 1: Determine what shape the base is:
Rectangle
Step 2: Find the area of the base
(8.5)(5) =
Step 3: Multiply by the height:
42.5(6) =
42.5
6 in.
255 in3
5 in.
8.5 in.

9. Find the volume of the triangular prism
Step 1: Determine what shape the base is: Triangle
Step 2: Find the area of the base
½ (12)(10) =
Step 3: Multiply by the height:
60(14)=
14 ft 60
12 ft
To find the area of a triangle multiply ½(base)(height)
840 ft 3
10 ft
12 ft

10. Find the volume of the cylinder.
Step 1: Determine what shape the base is: circle
Step 2: Find the area of the base
p (52) =
Step 3: Multiply by the height:
25 p(15)=
15 in.
25p
375p in3
Area of a circle is found by multiplying p by radius squared.
Radius = 5 in!

11. Steps for finding Volume:
Find the area of the base.
Multiply by height.
All units used are cubed (3)