If the perimeter of the rectangle is 34 cm and we increase its length by 2.5 cm then there will be a difference of ______ cm in its perimeter.
If the perimeter of the rectangle is 34 cm and we increase its length by 2.5 cm then there will be a difference of ______ cm in its perimeter.
Explanation
L = length, W = width
Perimeter = 2(L + W) = 34 cm
If length increases by 2.5 cm:
New perimeter = 2(L + 2.5 + W)
= 2L + 5 + 2W
= 2(L + W) + 5
= 34 + 5
= 39 cm
Difference in perimeter = 39 - 34 = 5 cm