Question

Question 29

If the sides of a parallelogram are increased to twice its original lengths, how much will the perimeter of the new parallelogram increase?

(a) 1.5 times
(b) 2 times
(c) 3 times
(d) 4 times

Answer 1

Let the length and breadth of the parallelogram be l and b, respectively.
Then, perimeter = 2(l + b) [$\because$ perimeter of parallelogram $=2\times (length+breadth)$]
If both sides are increased to twice, then new length and breadth will be 2l and 2b, respectively.
Now, new perimeter = 2(2l + 2b) = 2 x 2(l + b) = 2 times of original perimeter.
Hence, the perimeter of parallelogram will be increased to 2 times.