Area Problems The area of circle is 38.5 sq. cm. Its circumference is? 11 cm 6.20 cm 22 cm 121 cm 11 cm 6.20 cm 22 cm 121 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? ( 22 x r2) / 7 = 38.5? r2 =(38.5 x 7) /22? r = 3.5 cm? Circumference = 2 x (22/7) x 3.5 cm= 22 cm
Area Problems The area of an equilateral triangle whose side is 8 cms is? 64 cm2 21.3 cm2 4?3 cm2 16?3 cm2 64 cm2 21.3 cm2 4?3 cm2 16?3 cm2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Req. Area = ?3/4 x a2 = ?3/4 x 82 cm2= 16?3 cm2
Area Problems Diagonals of a rhombus area 1 m and 1.5 m in lengths. The area of the rhombus is 0.375 m2 1.5 m2 0.75 m2 1.5 m2 0.375 m2 1.5 m2 0.75 m2 1.5 m2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of rhombus =(d1 x d2)/2 =(1 x 1.5)/2 m2= 0.75 m2
Area Problems The cost of cultivating a square field at the rate of Rs. 160 per hectare is Rs. 1440. the cost of putting a fence around it at 75 paisa per meter is? Rs. 1800 Rs. 810 Rs. 900 Rs. 360 Rs. 1800 Rs. 810 Rs. 900 Rs. 360 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area = 1440 / 160 hectares = 9 hectares = 90000 m2? One side = ?90000 m = 300 mSo perimeter = 4 x 300 m = 1200 m ? Cost of fencing = Rs (1200 x 75) / 100= Rs. 900
Area Problems The length of a rectangle is twice its breadth. If its length is decreased by 5 cm and the breadth is increased by 5 cm, the area of the rectangle is increased by 75 cm 2 . Therefore , the length of the rectangle is? 50 cm 40 cm 20 cm 30 cm 50 cm 40 cm 20 cm 30 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let breadth = b, length = 2b? Area of rectangle = 2b x b = 2b2As per question. ? (2b - 5 ) (b + 5 ) = 2b2 + 75? 5b = 75 + 25? 5b = 100? b = 100 / 5 = 20Hence, length of the rectangle =2b = 2 x 20 = 40 cm.
Area Problems The area of circle inscribed in an equilateral triangle is 462 cm . The perimeter of the triangle is? 72.6 cms 42 ? 3 cms 168 cms 126 cms 72.6 cms 42 ? 3 cms 168 cms 126 cms ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? 22/7 x r2 = 462? r2 = (462 x 7) /22 = 147? r = 7?3 cm ? Height of the triangle = 3r = 21?3 cmNow, ? a2 = a2/4 + (3r)2? 3a2/4 = (21?3)2? a2 = (1323 x 4)/3? a = 21x 2 = 42 cm? Perimeter = 3a = 3 x 42=126 cm
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