Question

the length of a rectangle is one centimetre more than 2 times its breadth its perimeter is 80 cm what is its length

Answer 1

Let the breadth be x cm.

Length= 2x+1


Perimeter=2(l+b)
80=2(2x+1+x)
40=3x+1
3x=39
x=13cm


LENGTH=2*13+1=27cm
BREADTH=13cm

Answer 2

Hey!!

______________

Let the breadth be 'w'

=> Length = 2w + 1 【Acc. to question】

Also,
Perimeter = 80 cm

=> 2( l + b ) = 80 cm

=> 2( w + 2w +1 ) = 80

=> 3w + 1 = 40

=> 3w = 39

=> $\fbox{w = 13}$

so,
Length = w = 13cm

Breadth = 2w + 1 = 2(13) + 1 = 27 cm