Since Rectagle area is found by Length * Width, 20/8 would give the width of 2.5cm, if the length was increased by 2cm, and the area by 4cm, you would now do 24/10 to get the width which is 2.4, 5 percent of 2.5 is found by multiplying 2.5 by 0.05 which is 0.125, and 2.4 is only .1 less from 2.5 so yes noah is indeed correct, for that the width is decreased by less than 5%
