Question

if the difference between the length and breadth of a rectangle is 20 m and its area is 400 m2, then calculate the perimeter of the rectangle.

Answer 1

Here l-b=20( l and b are the usual symbols for length and breadth ).The area of rectangle being lxb=400 => (l+b)²=4lxb+(l-b)²=> (l+b)²=4.400+20²=2000=>

(l+b)=√(2000)=20√5.Perimeter being 2(l+b)=2x20√5=89.44m