1. Perimeter & Area 5.1

2. Define perimeter and area. Find the perimeter of a figure. Use two methods to find the area of compound figures. Apply the area and formula of a rectangle and triangle. Approximate the area of an irregular figure. Apply area to real world situations.

3. Area The number of square units needed to cover the region inside a figure. Area is always measured in square units! There are 40 squares covering the inside of the figure.

4. Area To calculate the area of a rectangle use the formula: Area = Length x Width Area = 9m x 2m Area = 18 square meters

5. Area To calculate the area of a triangle use the formula: Area = ½ Base x Height

6. Perimeter The perimeter is the distance around a figure. Start Start at one of the vertices and sum the numbers clockwise or counterclockwise. 10 + 6 + 4 + 10 + 10 + 6 + 4 + 10 = 60 m

7. Find the Area & Perimeter perimeter 12 in a. b.c. 5 inches 3 inches Perimeter = 20 inches Area = 9 inches² area 5 in 2 perimeter 20 cm about 9 cm 2 perimeter 16 cm about 7 cm 2

8. This side was 8m but because you split it to make two regular rectangles, look carefully at every side of the figure to see what the new measurements will be! Don’t forget the rule, opposite sides are equal! This will help you find the missing measurements! Find the area of rectangle “A” A= L x W A = 4m x 4m A = 16 square m Find the area of rectangle “B” A= L x W A = 10m x 4m A = 40 square m 40 square m + 16 square m 56 square m The total area is 56 square m. Find the Area

9. 10cm 8cm 2cm 4cm Area = 4 x 10 40cm 2 Area = 4 x 8 32cm 2 Total area = 40 + 32 = 72 cm 2 A shape that is made from other shapes is known as a composite shape. To find the area of this shape we have to split it up into two rectangles. Area

10. 9cm 5cm 2cm 4cm 5cm 4cm 2cm Area = 5 x 9 45cm 2 Area = 4 x 5 20cm 2 Total area = 45 + 20 = 65 cm 2 Perimeter = 36 cm Area & Perimeter

11. 6cm 11cm 2cm 4cm 5cm Area = 2 x 5 10cm 2 Area = 6 x 6 36cm 2 Total area = 10 + 36 = 46 cm 2 Perimeter = 34 cm Area & Perimeter

12. 11cm 7cm 4cm 3cm 7cm Total area = 28 + 16 + 21 = 65 cm 2 Perimeter = 42 cm Area = 4 x 7 Area = 4 x 4 4cm Area = 3 x 7 21cm 2 28cm 2 16cm 2 There is another way of doing this question.

13. 7cm 4cm 3cm 7cm Total area = 77 – 12 = 65 cm 2 Perimeter = 42 cm Area = 7 x 11 Area = 3 x 4 4cm 77cm 2 12cm 2 Lost Area Method

14. 9cm 5cm 2cm 4cm 5cm 4cm 2cm Find the area using composition of area method A = 5 x 9 + 5 x 4 A = 45 + 20 A = 65 cm 2

15. 6cm 11cm 2cm 4cm 5cm Find the area using the lost area method A = 6 x 11 – 5 x 4 A = 66 – 20 A = 46 cm 2

16. Find the area of the figure. Total area = 16(14) – 60 – 60 = 104 m 2

17. Total area= 3,560 square ft. Find the area of the figure.

18. $64.80 Mike is remodeling his kitchen. The countertop he wants costs $2.70 per square foot. How much will Mike have to spend on his remodeling project? Total area = 12 + 12 = 24 ft 2 Price per square foot $2.70 2.70 x 24 Answer the following question.

19. Approximate Area of an Irregular Figure There are 8 squares completely inside the figure (X) and 12 partly inside the figure ().

20. Count the complete squares. X X X X Count the partial squares.         Approximate Area of an Irregular Figure

21. about 7.5 cm 2 Estimate the shaded area. The grid has squares with side lengths of 1 cm. about 7 cm 2 a. b.

22. about 10.5 cm 2 Estimate the shaded area. The grid has squares with side lengths of 1 cm. a.

23. Find the area of the composite figure that is made up of known shapes Add the area of the rectangle to the area of the two triangles. A  = l x w A  = 6 x 5 A = 30 units 2 Total Area = 30 + 2.5 + 9 Total Area = 41.5 units 2

24. 4cm 6cm 8cm 2cm Find the area. about 40 cm 2 about 24 cm 2 a. b.

25. 15 x 20 = 300 square units 2(15) + 2(20) = 70 units 3 x 20 = 60 square units 2(3) + (2)20 = 46 units 8 x 13 = 104 square units Answer each of the following questions.

26. Assignment 5.1A 1 - 8 and 5.1B 1 - 10 Day 2 Basic Area 1 – 29