The area of rectangle is 1.8 times the area of a square. The length of the rectangle is 5 times the breadth. The side of the square is 20 cm. What is the perimeter of the rectangle?

• A. 135 cm
• B. 144 cm
• C. 145 cm
• D. 133 cm

Answer: (B)

Area of square = (Side)2 = 202= 400 sq cm ? Area of rectangle = 1.8 x 400 = 720 sq cm Let length and breadth of rectangle be 5k and k respectively.Then, according to the question, 5k x k = 720? 5k2 = 720 ? k2 = 720/5 = 144? k = ?144 = 12 cm Perimeter of rectangle = 2(5k + k) = 12k= 12 x12 = 144 cm