Page 680 - Basic College Mathematics with Early Integers

S E C T I O N 9.4 I AREA 657

41. The outlined part of the roof shown is in the shape of 42. The entire side of the building shaded in the drawing
a trapezoid and needs to be shingled.The number of is to be bricked.The number of bricks to buy
shingles to buy depends on the area. depends on the area.
a. Use the dimensions given to find the area of the a. Find the area.
outlined part of the roof to the nearest whole
square foot.

4 feet
36 ft
12 feet
12q ft 25 ft 12 feet
8 feet

b. Shingles are packaged in a unit called a “square.” b. If the side area of each brick (including mortar
If a “square” covers 100 square feet, how many 1
room) is square ft, find the number of bricks
whole squares need to be purchased to shingle 6
this part of the roof? that are needed to brick the end of the building.

Review

Find the perimeter or circumference of each geometric figure. See Section 9.3.

43. Give an exact circumference and 44. 45. 3 ft 3q ft
an approximation. Use 3.14 for p. 4 cm 5 cm
4 ft
Rectangle 6 ft
14 in.
8q ft

46. 6 mi 47. 2Ω ft 48. Equilateral triangle

9~ mi 3 in.
Regular
7q mi hexagon

12 mi

Concept Extensions

Given the following situations, tell whether you are more likely to be concerned with area or perimeter.

49. ordering fencing to fence a yard 50. ordering grass seed to plant in a yard

51. buying carpet to install in a room 52. buying gutters to install on a house

53. ordering paint to paint a wall 54. ordering baseboards to install in a room

55. buying a wallpaper border to go on the walls around 56. buying fertilizer for your yard
a room