Area Problems If the circumference of a circle is the 352 meters, then its area in m square is? 8956 5986 6589 9856 8956 5986 6589 9856 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP circumference = 2?r = 2 x (22 / 7) x r = 352? r = (352 x 7) / (22 x 2) =56 cmNow area = ?r2 = (22 / 7) x 56 x 56 m2= 9856 m2
Area Problems The area of rectangle whose length is 5 more than twice its width is 75 sq units. What is the perimeter of the rectangle? 20 unit 40 unit 30 unit 24 unit 20 unit 40 unit 30 unit 24 unit ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the width of the rectangle = k units? Length = (2k + 5) units.According to the question,Area = k(2k + 5)? 75 = 2k2 + 5k? 2k2 + 5k - 75 = 0 ? 2k2 + 15k - 10k - 75 = 0 ? k(2k + 15) - 5(2k + 15) = 0 ? (2k + 15) (k - 5) = 0 ? k = 5 and -15/2Width cannot be negative. ? Width = 5 units? Length = 2x + 5 = 2 x 5 + 5 = 15 unit? perimeter of the rectangle = 2(15 + 5) = 40 units
Area Problems If the base of a rectangular is increased by 10% and the area is unchanged , then the corresponding altitude must to be decreased by? 11% 91/11 % 10% 111/9 % 11% 91/11 % 10% 111/9 % ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let base = b and altitude = h Then, Area = b x h But New base = 110b / 100 = 11b / 10Let New altitude = HThen, Decrese = (h - 10h /11 )= h / 11? Required decrease per cent = (h/11) x (1 / h ) x 100 %= 91/11 %
Area Problems The perimeter of an equilateral triangle is 90 cm. Find its area. 250?3 sq cm 151?3 sq cm 135?3 sq cm 225?3 sq cm 250?3 sq cm 151?3 sq cm 135?3 sq cm 225?3 sq cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Given that, perimeter = 90 cm? 3a = 90 cm [a = side]? a = 90/3 = 30 cm? Area = ?3a2 / 4 = ?3/4 x (30)2= 900 x ?3/4 = 225?3 sq cm
Area Problems The ratio of the area of a square to that of the square drawn on its diagonal is 2;3 4:1 3:1 1:2 2;3 4:1 3:1 1:2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP atio = a 2 2 a 2
Area Problems A wheel make 4000 revolution in moving a distance of 44 km. Find the radius of the wheel. 27 m 25 m 1.75 m 28 m 27 m 25 m 1.75 m 28 m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Distance covered in 1 revolution = (44 x 1000) / 4000 = 11 mAccording to the question, 2?r = 11 ? (44/7) x r = 11? r = (11 x 7) / 44 = 1.75 m
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