Question

The perimeter of rectangle is 54cm and area is 180sqcm. Find tje length and breadth

Answer 1

Perimeter of rectangle = 2(l+b)

54 =2(l+b)

l+b=27    (equation 1 )

area of rectangle = l*b

180=l*b

b=180/l    (equation 2)

put equation 2 in equation 1

l+180/l=27

l²+180=27l

l²-27l+180 =0

l²-12l-15l+180=0

l(l-12)-15(l-12)=0

(l-15) (l-12) =0

l=15 or l=12

put l =15 in equation 1

l+b=27

15 + b=27

b=12

there fore length =15cms and breadth is 12cms