A rectangle carpet has an area of 120 square metres and a perimeter of 46 m The length of its diagon...........

Explanation:

l × b = 120 and 2 (l + b) = 46 => (l + b) = 23 
(l - b)^2 = (l + b)^2 - 4lb = (23)^2 - 4 × 120 = (529 - 480) = 49 => l - b = 7
On solving l + b = 23, l - b = 7, we get : l = 15, b = 8 
Diagonal = √(15)^2 + 8^2 = √(225 + 64) = √289 = 17 m