Perimeter and Area of Composite Figures Composite Figure

Perimeter and Area of Composite Figures

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

Perimeter: Is the distance around a figure 7 cm 5 c 3 cm m ? 7 cm P = 7 cm + 5 cm + 4 cm + 7 cm 4 cm + 4. 71 cm P = 27. 71 cm The perimeter of a circle has a special name, It is called the _______, circumference and is found using either of these formulas:

Alice is putting a wallpaper border around her bedroom. She perimeter of her bedroom in order to must find the _____ purchase the correct amount of border. 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? 3 yd 14 yd 6 yd 10 6 yd 8 yd yd 10 yd 8 yd Area of Semi-Circle + Area of Rectangle + Area of Triangle

Detective Le. Rue must investigate a crime committed at the local park. How many square meters of ground must he cover when looking for clues? 2 2 Total area = 28 m + 16 m + 21 m = 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 4 m 16 m 2 Area =3 m(7 m) 21 m 2 7 m 7 m 3 m 28 m 2 2

• 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 2 2 = 77 m – 12 m = 65 square meters How can we use subtraction to find the area? 11 m 4 m 3 m 4 m Area =7 m (11 m) = 77 m 2 7 m 7 m 3 m 4 m Area = 3 m(4 m) =12 m 2

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

1. Find the area and perimeter 6 cm 2 cm 5 cm 9 cm Area = 74 cm 2 Perimeter = 40 cm 5 cm

2. Find the area and perimeter 30 in Area = 2300 in 2 Perimeter = 240 in 70 in 20 in

3. Find the area and perimeter 3 yd 4. 5 yd 2 yd 3 yd Area = 30 yd 2 Perimeter = 29 yd 8 yd

4. Find the area and perimeter. Use 3. 14 for π Area = 88. 26 ft 2 Perimeter = 38. 84 ft

5. Find the area and perimeter Area = 212. 75 km 2 Perimeter = 69. 7 km 14 km 18 km

6. Find the area and perimeter 3 m Area = 97. 5 m 2 Perimeter= 36 m 12. 5 m 7. 5 m 13 m

7. Find the area of the arrow. Area = 90 ft 2

8. Find the Area of the Shaded Region. Use 3. 14 for π. Area = 437. 5 mm 2