1. Warm Up
Problem of the Day
Lesson Presentation
Lesson Quizzes

2. Warm Up
prism

3. Problem of the Day
Which figure has the longer side and by how much: a square with an area of 81 ft2 or a square with perimeter of 84 ft?
a square with a perimeter of 84 ft; by 12 ft

4. Objective:
To find the surface areas of prisms

5. Vocabulary
Surface Area: Total area of the 2D surfaces (faces and bases) that make up the area of a 3D object
Net: A 2D representation of a 3D figure that can be folded and glued to make the 3D object

6. Since a net is the pattern made when the surface of a 3D figure is laid out flat showing each face/base of the figure. The surface area of the 3D figure is the sum of the areas of its surfaces (faces/bases). The net helps you see all the surfaces of a 3D figure.

7. Additional Example 1A: Finding the Surface Area of a Prism
Find the surface area SA of the prism.
Method 1: Use a net.
Draw and label a net to help you see each face of the prism.
What area formula(s) should be used to find the areas of the 2D polygons that makes the prism?

8. Additional Example 1A Continued
A: A = 5  2 = 10
B: A = 12  5 = 60
C: A = 12  2 = 24
D: A = 12  5 = 60
E: A = 12  2 = 24
F: A = 5  2 = 10
Add the areas of each face.
S = = 188
The surface area is 188 in2.

9. Additional Example 1B: Finding the Surface Area of a Prism
Find the surface area SA of each prism.
Method 2: Use a three-dimensional drawing.
Find the AREA of the front, top, and side, and multiply each by 2 to include the opposite faces/bases.

10. Additional Example 1B Continued
Front: 9  7 = 63
63  2 = 126
Top: 9  5 = 45
45  2 = 90
Side: 7  5 = 35
35  2 = 70
S = = 286
Add the areas of each face.
The surface area is 286 cm2.

11. Check It Out: Example 1A
Find the surface area S of the prism.
Method 1: Use a net. A
3 in.
3 in.
6 in.
6 in.
3 in.
3 in.
6 in.
11 in.
11 in. B C D E F
3 in.
Draw and label a net to help you see each face of the prism.
Use the formulas to find the area of each face.

12. Check It Out: Example 1A
A: A = 6  3 = 18 A
3 in.
B: A = 11  6 = 66
3 in.
6 in.
6 in.
3 in.
C: A = 11  3 = 33
11 in.
D: A = 11  6 = 66 B C D E
E: A = 11  3 = 33 F
3 in.
F: A = 6  3 = 18
Add the areas of each face.
S = = 234
The surface area is 234 in2.

13. Check It Out: Example 1B
Find the surface area SA of each prism.
Method 2: Use a three-dimensional drawing.
top
side
front
8 cm
10 cm
6 cm
Find the area of the front, top, and side, and multiply each by 2 to include the opposite faces.

14. Check It Out: Example 1B Continued
top
side
front
8 cm
10 cm
6 cm
Front:  6 = 48
48  2 = 96
Top:  6 = 60
60  2 = 120
Side:  8 = 80
80  2 = 160
S = = 376
Add the areas of each face.
The surface area is 376 cm2.

15. What if the 3D shape was a Cube. How could you find the Surface Area
What if the 3D shape was a Cube? How could you find the Surface Area? Can you think of a formula that would work?
SA of a Cube = 6s2
SA = 6(3)2
SA = 6 x 9
SA = 54 cm2
3cm
3 cm

16. Lesson Quizzes
Standard Lesson Quiz
Lesson Quiz for Student Response Systems

17. 214 ft2 54 ft2 140 m2 194.94 cm2 Lesson Quiz: Find the surface area.
1. A rectangular prism with base length 6 ft, width 5 ft, and height 7 ft
2. A cube with side length 3 ft
Find the surface area of the figures shown.
214 ft2
54 ft2
5 m
140 m2
4 m
3 m
cm2
8 m

18. Lesson Quiz for Student Response Systems
1. Find the surface area of a rectangular prism with base length 7 ft, width 6 feet, and height 9 ft.
A. 318 ft2
B. 306 ft2
C. 300 ft2
D. 298 ft2

19. Lesson Quiz for Student Response Systems
2. Find the surface area of a cylinder with radius 5 ft and height 8 ft. Use 3.14 for .
A ft2
B ft2
C ft2
D ft2

20. Lesson Quiz for Student Response Systems
3. Find the surface area of the figure shown.
A. 162 ft2
B. 152 ft2
C. 142 ft2
D. 132 ft2