If the length of a rectangle is increased by 10% and the width of the rectangle is decreased by 10%, is the area changed? If so, does it increase or decrease and by what percent? Explain your answer.

Answer 1

since a=lw, your new area is

(1.1l)(0.9w) = 0.99 lw

So the area has decreased by 1%

Answer 2

Well, you could say: since every square is a rectangle 'because it is a quadrilateral with all four angles right angles,' therefore the area didn't change.