the perimeter of a rectangle is 240 cm . if its lenghtis increased by 10 %n its breadth is increased by 20%,we get the same perimeter > find the length n breadth of the rectangle ??
Suppose l and b be the length and breadth of the rectangle respectively.
So perimeter of rectangle =
when length is decreased by 10%, then new length =
And when breadth is increased by 20%, then new breadth =
So, according to the question we have;
Perimeter =
Now multiplying (i) by 3 and subtract (ii) from (i) we get;
Putting b = 40 in (i) we get;
Therefore length and breadth of rectangle are 80 cm and 40 cm respectively.
So perimeter of rectangle =
when length is decreased by 10%, then new length =
And when breadth is increased by 20%, then new breadth =
So, according to the question we have;
Perimeter =
Now multiplying (i) by 3 and subtract (ii) from (i) we get;
Putting b = 40 in (i) we get;
Therefore length and breadth of rectangle are 80 cm and 40 cm respectively.