Question

the length of a rectangle is 5cm more than its breath.if the perimeter of the rectangle is 40 cm. find the dimention of the rectangle?

Answer 1

L=5+b,p=40cm.
Perimeter of a rectangle =2(l+b)
40=2(5+b+b)
40=10+4b
30/4=b
b=7.5
l=12.5

Answer 2

Let the breadth of the rectangle be x.
According to the given conditions
Length = x+5
breadth = x
perimeter= 40cm
perimeter= 2(l+b)
      40     = 2( x+5+x )
      40     = 2( 2x+5 )
      40.    = 4x+10
      40-10 = 4x
      30.    =  4x
      30/4  = x
       x = 7.5
breadth = 7.5 cm
length = 7.5+5
          =. 12.5cm