Area Problems The ratio of the radii of two circle is 1:3 the radio of their areas is? 1:9 1:6 1:3 None of these 1:9 1:6 1:3 None of these ANSWER EXPLANATION DOWNLOAD EXAMIANS APP The Radio of areas = area of first circle : area of 2nd circle= ?r2 / ?(3r)2= ?r2/ 9 ?r2= 1/9 = 1: 9
Area Problems The diagonal of the floor of a rectangular closet is 7½ feet. The shorter side of the closet is 4½ feet. What is the area of the closet in square feet? 13(1/2) 37 27 5(1/4) 13(1/2) 37 27 5(1/4) ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Other side = (15 / 2) 2 - (9 / 2) 2 ft = (225 / 4) - (81 / 4) ft = 144 / 4 ft = 6 ft Area of closet = (6 x 4.5) sq. ft = 27 sq. ft.
Area Problems In a circle of radius 21 cm an arc subtends an angle of 72° at the centre. The length of the arc is? 13.2 cm 19.8 cm 26.4 cm 21.6 cm 13.2 cm 19.8 cm 26.4 cm 21.6 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Arc length = 2?r (?° / 360°) = 2 x (22/7) x 21 x (72° / 360°) cm= 26.4 cm
Area Problems The area of a rectangle, 144 m long is the same as that of a square having a side 84 m long. The width of the rectangle is? Cannot be determined 49 m 7 m 14 m Cannot be determined 49 m 7 m 14 m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of the square = (84 + 84) m2Area of the rectangle = (144 x width) m2From question both area would be same,? Width = (84 x 84) / 144 m = 49 m
Area Problems If the radius of a circle is decreased by 50% , find the percentage decrease in its area. 65% 35% 75% 25% 65% 35% 75% 25% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP let original radius = r and new radius = (50/100) r = r/2 original area = ?r 2 and new area = ? r / 2 2 decrease in area = 3 ?r 2 / 4 * 1 ?r 2 *100 = 75%
Area Problems If 88 m wire is required to fence a circular plot of land, then the area of the plot is? 556 m2 526 m2 616 m2 None of these 556 m2 526 m2 616 m2 None of these ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Circumference of circular plot= 88 m? 2 x (22/7) x r = 88? r = 88 x (7/22) x (1/2) = 14 m Now area = ?r2=( 22/7) x 14 x 14 m2= 616 m2
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