Question

The area of a small rectangular plot is 84 m2
If the difference between its length and the
breadth is 5 m; find its perimeter.​

Answer 1

Step-by-step explanation:

let us consider length as l m and breadth as b m.

Area of rectangular plot = 84 m^2

l - b = 5m

=> l = 5+b

A = l × b

84 = (5+b)×b

84 = 5b+b^2

b^2+5b-84 = 0

b^2+12b-7b-84 = 0

b(b+12)-7(b+12) = 0

b+12 = 0 or b-7 = 0

b = -12 or b = 7m

breadth is 7cm, b= - 12 is negative number, therefore it is rejected.

length = 5 + b

length = 5+7

l = 12 m

Perimeter of rectangular plot is = 2(l+b)

P = 2(12+7)

P = 2(19)

P = 38 m