Area Problems If the area of a semi-circle be 77 sq m, find its perimeter. 48 m 42 m 54 m 36 m 48 m 42 m 54 m 36 m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP According to the question, Area of semi- circle = 77 m(1/2) x ? x r2 = 77? r2 = (77 x 2 x 7)/22? r = 7m ?Circumference of semi- circle =?r + 2r= ( ? + 2)r = [(22/7) + 2] x 7 = 36 m
Area Problems The Area of a square is 50 sq. units. Then the area of the circle drawn on its diagonal is? 50? sq. units 25? sq. units None of theas 100? sq. units 50? sq. units 25? sq. units None of theas 100? sq. units ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area = (Diagonal)2 / 2 = 50? Diagonal = 10 units ? Radius of required circle = 5 unitsIts area = [? x (5)2 ] cm2= 25? units2
Area Problems A wire can be bent in the form of a circle of radius 56cm. If it is bent in the form of a square, then its area will be 7744 5544 8844 4444 7744 5544 8844 4444 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP length of wire = 2 ?r = 2 x (22/7 ) x 56 = 352 cmside of the square = 352/4 = 88cmarea of the square = 88 x 88 = 7744sq cm
Area Problems If 88 m wire is required to fence a circular plot of land, then the area of the plot is? 526 m2 None of these 616 m2 556 m2 526 m2 None of these 616 m2 556 m2 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
Area Problems if the side of a square be increased by 4 cms. The area increased by 60 sq. cms . The side of the square is? None of these 12 cm 13 cm 14cm None of these 12 cm 13 cm 14cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let each side = x cmThen, (x + 4 )2 - x2 = 60? x 2 + 8x + 16 - x2 = 60? x = 5.5 cm
Area Problems If the radius of a circle be reduced by 50%. Its area is reduced by? 34.5% 31.5% 39.5% 65.5% 34.5% 31.5% 39.5% 65.5% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Original area = ? x (r/2)2 = ?r2/4Reduction in area = ? r2 - 3? r2/4? Reduction per cent = [ 3?r2/4 x 4/(?r2) x 100 ] %= 75%
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