1. Area of Composite Shapes
We are learning to…find the area of composite shapes (shapes made up of more than one figure).

2. Area of Composite Shapes Review of Important Area Formulas
Area of a Rectangle:
A = b(h)
Area of a Triangle:
A = ½(b)(h)
Area of a Circle:
A = πr2
Area of a Parallelogram:
Area of a Trapezoid:
A = ½(b1 + b2)h

3. Area of Composite Shapes Example #1: Find the area of the composite shape below.
10 feet
4 feet
Plan:
Area of a Rectangle
+ Area of ½ Circle
l(w)
+ ½ πr2
4(10)
+ ½ π(2)2
4(10) + ½ π(4)
Diameter = 4 feet
40 + ½ π(4)
Radius = 2 feet
40 + (1.57)(4)
46.28 square feet

4. Area of Composite Shapes Example #2: Find the area of the shaded region.
Plan:
Area of a Square
- Area of Circle
4 cm
l(w)
- πr2
4 cm
4(4)
- π(2)2
4 cm
4(4) - π(4)
16 - π(4)
4 cm
3.44 square cm

5. Area of Composite Shapes Example #3: Find the area of the shaded region.
Plan:
6 in
5 in
4 in
12 in
Area of a Trapezoid
- Area of a Triangle
½(b1 + b2)(h)
- ½(b)(h)
½(6 + 12)(4)
- ½(6)(4)
½(18)(4) - ½(6)(4)
36 - ½(6)(4)
24 square inches

6. Area of Composite Shapes Example #4: Find the area of the shaded region.
Plan:
8 ft
15 ft
6 ft
10 ft
Area of a Trapezoid
- Area of a Circle
½(b1 + b2)(h)
- πr2
½(6 + 15)(8)
- π(4)2
½(21)(8) - π(4)2
½(21)(8) - π(16)
84 - π(16)
84 – 50.24
33.76 square feet

7. Individual Practice Try the last example with your team!
When you are done raise your hand and show your teacher the solution.

8. Area of Composite Shapes Example #5: Find the area of the polygon below.18 in
5 in
11 inches
9 inches
Plan:
Area of a Rectangle
+ Area of a Rectangle
l(w)
+ lw
18 – 5 = 13 inches
9(13)
+ 5(20)
(20)
217 Square inches
= 20 inches