Question

perimeter of a rectangle is 100cm . lenth is 30cm what is the breadth

Answer 1

perimeter of rectangle was

=2[l+b]

according to question

2[30+b]=100

2b=40

b=20

Answer 2

let us take the value of breadth as b

the perimeter is= 2(l+b)

                          = 2(30+b)= 100

                         = 60+2b=100

                         = 2b=100-60

                          = b= 40/2

                          = the breadth of rectangle is 20 cm