A rectangular park is to be designed whose breadth is 3 m less than its length. Its area is to be 4 square metres more than the area of a park that has already been made in the shape of an isosceles triangle with its base as the breadth of the rectangular park and of altitude 12 m (see Figure). Find its length and breadth.

Explanation

let length be `x ` m

let breadth be `(x-3) ` m

`/_ ABC ` has base = `(x-3) `m

altitude `= 12m`

area `(/_ABC = 1/2 xx (x-3) xx 12`

`= 6 (x-3) m^2`

area od DEBC`= x xx (x-3)`

`= x^2 - 3x m^2`

...