9.2 Geometry pg. 521

Finding the area.

160.4 m

40 m

36m27 m

9 m

Find the area of the large rectangle minus the area of the small rectangle.

40 x 36 – 27 x 9

35. A lot is 40 m by 36 m. A house 27 m by 9 m is built on the lot. How much area is left for a lawn?

1440 - 243

1197 m2

1197 m2

L x W – L x W

40. A standard sheet of typewriter paper is 8 ½ in. by 11. We generally type on a 7 ½ in. by 9 in. area of paper. What is the area of the margin?

8 1/2

11

7 1/2

9

Find the area of the larger rectangleminus the area of the smaller rectangle.

8.5 x 11 – 7.5 x 9

93.5 – 67.5

26 in2

26 in2

L x W – L x W

43. Find the area of the shaded region.

4 cmS2 x 5

Find the area of the squares.

42 x 5

16 x 5

80 cm2

11 mm

12.5 mm

2 mm

3 mm

5 mm

44. Find the area of the shaded region.

Find the area of the larger rectangle minus the area of the smaller rectangle.

12.5 x 11 – 5 x 6

6

11-5 6

137.5 - 30

107.5 mm2

L x W – L x W137.5- 30.0107.5

30 cm45. Find the area of the shaded region.

Find the area of the square minus the area of the triangle.

S2 – ½ BH30 x 30 – ½ (30) (15)

900 – (15) (15)

900 - 225

675 cm2

30 cm

30 cm

15 cm

46. Find the area of the shaded region.

12 in.

2 in.

6 in.4 in.

3 in. 3 in. 2 in.

Area of the rectangle minus area of small triangle minus area of large triangle.

L x W – ½ BH – ½ BH

12 x 6 – ½ (3) (2) – ½ (4) (4)

72 – (3) (1) – (2) (4)

72 – 3 - 8

61 in2

24

4

12 in.

Try numbers 48 and 50.