Question

The perimeter of a rectangular field is 36 m. Its length is 10 m. Find the area of the field

Answer 1

Answer:

80m sq

Step-by-step explanation:

____________________80m sq_________

Answer 2

Answer:

Let the length of the field = x

breadth = y

perimeter = 2(x+y) =80

⇒ x+y = 80/2

⇒ x+y = 40

Area = xy

If the length is decreased by 2m and breadth is increased by 2m,

new length = (x-2)

new breadth = (y+2)

area = (x-2)(y+2) = xy + 2x -2y - 4

this area is 36 m² more than earlier area. So

(xy + 2x -2y - 4) - (xy) = 36

⇒2x -2y - 4 =36

⇒2x - 2y = 36+4 = 40

⇒ x-y = 20

Add the 2 equations, we get

2x = 60

⇒ x = 30m

y = 10m

Hence length = 30m

breadth = 10m