Question

length of rectangle is 3 more than its breadth find the length and breadth if its area is 180 cm square​

Answer 1

Step-by-step explanation:

let, length be 'l' and breadth be 'b'

length of rectangle is 3 more than its breadth.

therefore,

l = 3 + b............(1)

Area of rectangle = length × breadth

180 = l × b

180 = (3+b) × b

180 = 3b + b^2

b^2 + 3b - 180 = 0

factors of -180 are 15 and -12

Therefore,

b^2 + 15b - 12b - 180 = 0

b ( b + 15 ) - 12 (b + 15 ) = 0

( b + 15 ) ( b - 12 ) = 0

b = -15 or b = 12

Since breadth cannot be negative

b = 12

l = 3 + b ( from 1)

l = 3 + 12

l = 15

Therefore length is 15 cm and breadth is 12 cm.