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**Perimeter and Area of Composite Figures**

For this topic, you need to know how to find the perimeter and area of rectangular shapes.

To review, see topics Perimeter and Compare Rectangle Area and Perimeter.

A **composite figure** is a figure that is made up of two or more basic shapes.

For example, putting two rectangles or a rectangle and a triangle together form composite figures.

**Example 1:** Perimeter and Area

**Find the perimeter and area of each figure. Each unit is 1 cm. Label your answers in "cm".
For example, "6 cm" and "12 sq cm"**

perimeter = area =

Perimeter

Add up the length of all the sides to get the perimeter.

Starting from point (1,6) and going clockwise, we get

Perimeter = 1 cm + 3 cm + 3 cm + 2 cm + 4 cm + 5 cm = 18 cm

Area

Calculate the area of the composite figure by adding up the areas of the smaller shapes that make up the composite figure .

The figure can be divided in different ways. Here are two examples:

Area = Areas of the two rectangles Area = Areas of the two rectangles = 3 sq cm + 8 sq cm = 5 sq cm + 6 sq cm = 11 sq cm = 11 sq cm

**Example 2:** Missing Sides

**The figure is made up of rectangles.**

To find the length of side , look at the two rectangles that make up the figure.A

Opposite sides of rectangles are the same length.

5 cm = A + 3 cm A = 2 cmTo find the length of side , look at the two rectangles that make up the figure.B

Opposite sides of rectangles are the same length.

8 cm = B + 4 cm B = 4 cm

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