unit 6 lesson 5
surface area of rectangular prisms practice
use the image to answer the question
4in, 2.25in.,8 in.
what is the surface area of the rectangular prism?
_ in^2
To find the surface area of a rectangular prism, you need to calculate the area of each of the six sides and then add them together.
The rectangular prism has 6 faces:
- Front and back: 2 rectangles with dimensions 4in by 2.25in, so each side has an area of 4in x 2.25in = 9in^2. Since there are 2 of these sides, the total area is 9in^2 x 2 = 18in^2.
- Top and bottom: 2 rectangles with dimensions 4in by 8in, so each side has an area of 4in x 8in = 32in^2. Since there are 2 of these sides, the total area is 32in^2 x 2 = 64in^2.
- Left and right sides: 2 rectangles with dimensions 2.25in by 8in, so each side has an area of 2.25in x 8in = 18in^2. Since there are 2 of these sides, the total area is 18in^2 x 2 = 36in^2.
Adding up the areas of all 6 sides:
18in^2 + 64in^2 + 36in^2 = 118in^2
Therefore, the surface area of the rectangular prism is 118in^2.