15. A park square in shape has a 3 metre wide road inside it running along its sides. The area occupied by the road is 1764 square metres. What is the perimeter along the outer edge of the road?
Answer:
Let the length of the outer edge be x metres. Then, length of the inner edge =
(x-6)m.
=> x2-(x-6)2 = 1764
=> x2-(x2-12x+36) = 1764
=> 12x = 1800 => x=150.
Required perimeter = (4x)m = (4*150)m = 600m.
