Question

If the area of a rectangle is 60 square centimetre, and its diagonal is 13 cm, then find its length, breadth and perimeter.

Answer 1

let length of rectangle is x and breadth of rectangle is y
then from property of rectangle
x^2+y^2=13^2=169 ----------(1)
now again ask
xy=60 cm^2
2xy=120 ----------(2)
add equation (1) and (2)
(x+y)^2=(17)^2=+_17
but here consider only positive part
x+y=17 --------(3)
now subtract equation (1) to (2)
(x-y)^2=(7)^2
x-y=+_7
hence x-y=7-------------(4)
now solve equation (3) and (4)
x=12cm and y=5cm

and perimeter of rectangle=2 (12+5)=34cm