# Perimeter and Area of Composite Figures

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Perimeter and Area of Composite Figures

Composite Figure: a figure that is made by combining triangles, quadrilaterals, semi-circles and other two-dimensional figures.

Perimeter: Is the distance around a figure
7 cm 5 cm 3 cm ? 7 cm 4 cm P = 7 cm + 5 cm + 4 cm + 7 cm cm P = cm The perimeter of a circle has a special name, It is called the ______________, and is found using either of these formulas: circumference

Alice needs to purchase 37 feet of border.
Alice is putting a wallpaper border around her bedroom. She must find the __________ of her bedroom in order to purchase the correct amount of border. perimeter 12 ft 3 ft ? 4 ft 6.5 ft ? 3.5 ft 8 ft P = 8 ft + 6.5 ft + 12 ft + 3 ft + 4 ft + 3.5 ft Alice needs to purchase 37 feet of border.

The area of a composite figure can be found by adding or subtracting the areas of the simpler figures that compose the composite figure. Area of Semi-Circle + Area of Rectangle + Area of Triangle

Joe has to mow the lawn of the field below, how many square yards must he mow?
14 yd 3 yd 10 yd 10 yd 6 yd 6 yd 8 yd 8 yd Area of Semi-Circle + Area of Rectangle + Area of Triangle

Is there another way of finding this area?
Detective LeRue must investigate a crime committed at the local park. How many square meters of ground must he cover when looking for clues? Total area = 28 m m m2 = 65 square meters Is there another way of finding this area? Area = 4 m (7 m) Area = 4 m(4 m) 4 m 3 m 3 m Area =3 m(7 m) 4 m 28 m2 7 m 21 m2 7 m 16 m2

How can we use subtraction to find the area?
Step 1: Find area of big rectangle Step 2: Find area of smaller rectangle Step 3: Subtract the smaller area from the larger area Total area = 77 m2 – 12 m2 = 65 square meters How can we use subtraction to find the area? 11 m 4 m 4 m 3 m 3 m Area = 3 m(4 m) 4 m 7 m 7 m Area =7 m (11 m) =12 m2 = 77 m2

Detective LaRue must isolate the crime scene,
how much tape will he need? Perimeter = 7m + 4 m + 3 m + 4 m + 3 m + 3 m + 7 m + 11 m Detective LaRue needs 42 meters of crime scene tape. 4 m 3 m ? 3 m 4 m 7 m 7 m ?

Area = 74 cm2 Perimeter = 40 cm 1. Find the area and perimeter 6 cm

Area = 2300 in2 Perimeter = 240 in 2. Find the area and perimeter

Area = 30 yd2 Perimeter = 29 yd 3. Find the area and perimeter 3 yd

Area = 88.26 ft2 Perimeter = 38.84 ft 4. Find the area and perimeter.
Use 3.14 for π Area = ft Perimeter = ft

Area = 212.75 km2 Perimeter = 69.7 km 5. Find the area and perimeter

6. Find the area and perimeter
Area = 97.5 m2 Perimeter= 36 m 3 m 12.5 m 7.5 m 13 m

7. Find the area of the arrow.
Area = 90 ft2

Area = 437.5 mm2 8. Find the Area of the Shaded Region.
Use 3.14 for π . Area = mm2

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