1. Warm Up Problem
Which of the following statements is true for the equation 6x = 78?
A) To find the value of x, subtract 6 from 78.
B) To find the value of x, multiply 6 by 78.
C) To find the value of x, add 6 and 78.
D) To find the value of x, divide 78 by 6.

2. Surface Area of Rectangular Prisms
Lesson 10-3

3. Objectives I can find the surface area of rectangular prism.
I can explain the difference between surface area and volume.

4. Vocabulary
surface area – the sum of the areas of the faces

6. Example 1
Find the surface area of the rectangular prism. Find the area of each pair of faces (red). Add them up: = 292 So, the surface area is 292 sq. meters.

7. Got It?
1. Find the surface area of the rectangular prism.

8. Example 2
Find the surface area of the rectangular prism. Use the formula for surface area: S.A. = 2lh + 2lw + 2hw Front and back: Sides: 2(7)(4) = 56 2(5)(4) = 40 Top and bottom: 2(5)(7) = 70 Add them up: = 166ft²

9. Example 3
Find the surface area of the rectangular prism.

10. Got It?
2. Find the surface area of the rectangular prism.

11. Example 4
A geode is being sent in a gift box. The box measures 7 inches long, 3 inches wide, and 16 inches tall. What is the surface area of the box?
S.A. = 2lh + 2lw + 2hw
S.A. = 2(7)(16) + 2(7)(3) + 2(3)(16)
S.A. = 14(16) + 14(3) + 32(3)
S.A. =
S.A. = 362 sq. in.