Area Problems The base of a parallelogram is twice its height. If the area of the parallelogram is 338 sq.cm. Find its height? 14 cm 13 cm 16 cm 12 cm 14 cm 13 cm 16 cm 12 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let height =x Then, base =2x 2x * x = 338 =>x=13
Area Problems The diagonal of a rectangle is √41 cm and its area is 20 sq. cm. The perimeter of the rectangle must be: 20 cm 18 cm 9 cm 41 cm 20 cm 18 cm 9 cm 41 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP √l2 + b2 = √41. Also, lb = 20. (l + b)2 = (l2 + b2) + 2lb = 41 + 40 = 81 ⟹ (l + b) = 9. ∴ Perimeter = 2(l + b) = 18 cm
Area Problems The radius of the wheel of a vehicle is 70 cm. The wheel makes 10 revolutions in 5 seconds. The speed of the vehicle is? 32.72 km/hr. 31.68 km/hr. 29.46 km/hr. 36.25 km/hr. 32.72 km/hr. 31.68 km/hr. 29.46 km/hr. 36.25 km/hr. ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Circumference = 2?r = 2 x (22 / 7) x 70 cm = 440 cm Distance travelled in 10 revolutions = 440 x 10 cm = 4400 cm = 44 m? Speed = distance / time= 44 / 5 m/sec= (44 / 5) x (18 / 5) km/hr = 31.68 km/hr
Area Problems The perimeter of two square is 12 cm and 24 cm. The area of the bigger square is how many times that of the smaller? 4 times 5 times 3 times 2 times 4 times 5 times 3 times 2 times ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ratio of area of 2 squares = (ratio of perimeter of 2 squares)2= (24/12)2= 4
Area Problems The length of a rectangle is double while its breadth is halved. What is the percentage change in area? None of these 50 75 No change None of these 50 75 No change ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let length = l and breadth = bThen, area = lb New length = 2lAnd new breadth = b/2 ? New area = ( 2l ) x (b/2) = lbSo, there is no change in area .
Area Problems If the diagonal of a rectangle is 17cm long and its perimeter is 46 cm. Find the area of the rectangle. 130 140 110 120 130 140 110 120 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP let length = x and breadth = y then 2(x+y) = 46 => x+y = 23 x²+y² = 17² = 289 now (x+y)² = 23² => x²+y²+2xy= 529 => 289+ 2xy = 529 => xy = 120 area = xy = 120 sq.cm
EXAMIANS