The length and breadth of a rectangular park are in the ratio 7:3 and its perimeter is 400m . Find the area of the park

Let the length of rectangle = 7x m

breadth of rectangle = 3x m

perimeter = 400 m

so 2[7x + 3x] = 400

⇒ 2(10x) = 400

⇒ 20x = 400

⇒ x = 400/20 = 20

length = 140 m

breadth = 60 m

area = length × breadth = 140 × 60 = 8400 m²