Area of Complex Figures
7.3
Review
Vocabulary and Notes
Steps
1. Cut the shape into simple shapes that we
know the area formulas for.
2. Find the area of each part.
3. Add the areas together to find the area of
the complex shape.
Find the area of the complex figure.
The figure can be separated into a rectangle and two
congruent triangles.
Area of rectangle
Area of one triangle
5
Answer: The area of the figure is
square inches.
Find the area of the complex figure.
Answer:
Find the area of the complex figure. Round to the
nearest tenth.
The figure can be separated into two semicircles and a
rectangle.
Area of one semicircle
Area of rectangle
Answer: The area of the figure is about
square centimeters.
Find the area of the complex figure. Round to the
nearest tenth.
Answer:
SHORT-RESPONSE TEST ITEM Below are plans for
the new deck on the Obwena’s house. How many
square feet of wood will be needed if one square
represents two square feet?
Read the Test Item
You need to find the area
of the deck in square
units and then multiply
this result by 2 to find the
area of the deck in square
feet.
Solve the Test Item
Find the area of the deck by dividing it into smaller areas.
Region A
Square
or 4
Region B
Triangle
or 2
Region C
Rectangle
or 6
Region D
Rectangle
or 8
Region E
Triangle
Region F
Rectangle
Region G
Triangle
Region H
Square
Answer: The total area is
or
square units. So, 2(36) or 72 square feet of
wood is needed to make the deck.
SHORT-RESPONSE TEST ITEM Below are plans for
the new patio to be added in the Murphy’s back yard.
How many square feet of concrete will need to be
poured if one square represents two square feet?
Answer:
Review