Area Problems The perimeter of an equilateral triangle is 90 cm. Find its area. 225?3 sq cm 135?3 sq cm 250?3 sq cm 151?3 sq cm 225?3 sq cm 135?3 sq cm 250?3 sq cm 151?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 difference between the circumference and the radius of a circle is 37 cm. The area of a circle is? 111 sq. cm 259 sq. cm 154 sq. cm 148 sq. cm 111 sq. cm 259 sq. cm 154 sq. cm 148 sq. cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? 2?r - r = 37? [(2 x 22/7) -1]r= 37? 37r / 7= 37? r = 7 So, area of the circle =(22/7) x 7 x 7 cm2= 154 cm2
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? 36.25 km/hr. 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. 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 area of a square is equal to the area of a rectangle. The length of the rectangle is 5 cm more than a side of the square and its breadth is 3 cm less than the side of the square. What is the perimeter of the rectangle ? 15 cm 18 cm 26 cm 34 cm 15 cm 18 cm 26 cm 34 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the side of the square be 's' cm length of rectangle = (s+5) cm breadth of rectangle = (s-3)cm (s+5) (s-3) = s 2 - 5s - 3s - 15 = s 2 2s = 15 Perimeter of rectangle = 2(L+B) = 2(s+5 + s?3) = 2(2s + 2) = 2(15 + 2) = 34 cm
Area Problems If the sides of a rectangle are increased by 5%, find the percentage increase in its diagonals. 4% 6% 5% 9% 4% 6% 5% 9% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP According to the formula,Percentage increase in diagonals = 5%
Area Problems A wheel make 4000 revolution in moving a distance of 44 km. Find the radius of the wheel. 28 m 1.75 m 25 m 27 m 28 m 1.75 m 25 m 27 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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