Area Problems The ratio of the corresponding sides of two similar triangles is 3 : 4, The ratio of their areas is? 3 : 4 9 : 16 4 : 3 ? 3: 2 3 : 4 9 : 16 4 : 3 ? 3: 2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ratio of similar triangle = Ratio of the square of corresponding sides = (3x)2 / (4x)2 = 9x2 / 16x2 = 9/16 = 9 : 16
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 41 cm 18 cm 9 cm 20 cm 41 cm 18 cm 9 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 diameter of the driving wheel of a bus is 140 cm. How many revolution, per minute must the wheel make in order to keep a speed of 66 kmph ? 250 550 350 150 250 550 350 150 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Circumference = No.of revolutions * Distance covered Distance to be covered in 1 min. = (66 X1000)/60 m = 1100 m.Circumference of the wheel = 2 x (22/7) x 0.70 m = 4.4 m.Number of revolutions per min. =(1100/4.4) = 250.
Area Problems The ratio of the area of the circumcircle and the incircle of a square is 2 : 1 ?2 : 1 1 : 2 1 : ?2 2 : 1 ?2 : 1 1 : 2 1 : ?2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ratio of the areas of the circumcircle and incircle of a square = [(Diagonal)2?] / [(Side)2?]= [(Side x ?2)2] / (Side)2 = 2/1 or 2 : 1
Area Problems Four horses are be tethered at four concern of a square plot of side 63 meters, so that they just cannot reach one another. The area left ungrazed is? 850.5 m2 675.5 m2 785.8 m2 780.6 m2 850.5 m2 675.5 m2 785.8 m2 780.6 m2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area left ungrazed = [(63 x 63) - (4 x 1/4 x 22/7 x (63/2)2] m2= (63 x 63 - (99 x 63)/2 ) m2= 63 x (63 - 99/2) m2= 850.5 m2
Area Problems One side of a parallelogram is 14 cm. Its distance from the opposite side is 16 cm. The area of the parallelogram is? 210 sq. cm 56? sq. cm 224 sq. cm 112 sq. cm 210 sq. cm 56? sq. cm 224 sq. cm 112 sq. cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of parallelogram = Side of parallelogram x distance from the opposite side= 14 x 16 cm2= 224 cm2
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