Question

The length of diagonal of a rectangular land is 15 meter and the difference of length and breadth is 3 meter. Let us calculate perimeter and area.​

Answer 1

Let length be l and breadth be b

diagonal of a rectangle =sqrt(l^2+b^2)

sqrt(l^2+b^2)=15

squaring on both sides

l^2+b^2=225-------(1)

given l-b=3----------(2)

squaring on both sides

l^2+b^2-2lb=9

225-2lb=9(as l^2+b^2=225)

lb=108,from 2nd equation l-b=3

(b+3)(b)=108

b=9,-12(but breadth cannot be negative)

hence b=9,l=12

Area =lb=108

Perimeter=2(l+b)=42