Question

The perimeter of a parallelogram is 140 cm.If one of the side is longer than the other by 10 cm, find the length of each of it's side

Answer 1

Let the first side is x
then the second side become (x+10)
According to the question
2(x+x+10) =140
2(2x+10)=140
2x+10=70
2x=70-10
2x=60
x=30

first side=x=30cm
second side=x+10=40cm

Answer 2

hello users ...
solution:-
we have given that:
one of the side is longer than the other by 10 cm.

=> let the one side of parallelogram is = x 
and
second = ( x + 10 )

now 
perimeter = 2 * ( a +b) 

where a and b are two non parallel sides . 

=> 140 = 2 × [ x + (x +10) ]

=> 140 = 2× (2x + 10 )

=> 70 = 2x +10

=> 2x = 60 

=> x = 30 

Hence
one side of parallelogram is = 30 cm
and
other side = 30 + 10  = 40 cm 

@ hope it helps :)