The perimeter of a rectangle is 40 m. If its length is four metres less than five times its breadth, then find the area of the rectangle.

64m ^ 2

Step-by-step explanation:

Let, breadth of rectangle is x, then 5x−4 be the length of the rectangle.  

Perimeter of rectangle =2(l+b)

⇒40=2(l+b)

⇒40=2(5x−4+x)

⇒40=12x−8

⇒12x=40+8

⇒12x=48

⇒x=  

12

48

​  

⇒x=4

Breadth =4 meters  

Hence, length =5×4−4=20−4=16m

Therefore, area of rectangle =lb=16×4=64m ^2