1. Surface Area
7th Grade Math
Obj. 4c

2. Surface Area
Surface Area is the amount of exposed area on a 3-D object.
Surface Area is always measured in square units, just like Area is.

3. Surface Area Nets can be used to determine Surface Area.
If an object has flat faces, its Surface Area can be determined by finding the area of each face and adding them together.

4. Surface Area…
Used in “Everyday” Life.
When you wrap a present, you’re working with Surface Area and Nets.

5. Surface Area Surface Area…
We can use our knowledge of nets to calcualte
Surface Area…

6. Finding Surface Area Step 1: Unfold the figure by drawing it’s net.
Step 2: Find the area of each shape using formulas learned previously.
Squares – l x w
Triangles - ½ hb
Step 3: Add all of the figures areas together to get the total amount of area or surface area.

7. Finding Surface Area Rectangular Prism + + 2 cm x 14 cm = 28 cm2
8 cm x 14 cm = cm2 cm2
14 cm +
156 cm2 +
2 =
312 cm2

8. Finding Surface Area Rectangular Prism SA = 2lw + 2lh + 2wh
8 cm
= 2(14)(2) + 2(14)(8) + 2(2)(8)
= 2(28) (112) (16) =
= 312 in2
2 cm
14 cm

9. Finding Surface Area Pyramid SA = ½Pl + B P = perimeter of the base
l = slant height
B = area of the base
9 cm
8 cm
8 cm
SA = ½Pl + B
= ½ (8)(4)(9) + 8(8) =
= 208 cm2

10. You Try!
Directions:
Find the surface area (SA) of each shape. Write your answers in units squared.
A rectangular prism with a length of 10, a width of 5 and a height of 3.
A square pyramid with a base of 5 and a slant height of 6.

11. You Try!
Directions:
Find the surface area (SA) of each shape. Write your answers in units squared.
A rectangular prism with a length of 10, a width of 5 and a height of 3.
A square pyramid with a base of 5 and a slant height of 6.
190 85