Sheet # 88 Critical Thinking
Name: _____________________ Date_____________
Use drawings, words, or numbers to explain how you got your answer.
If the width of a rectangle is increased by 10% and the length is decreased by 20%, by what percent does the area decrease or increase?
Answers for sheet # 88
Length of the rectangle: a
Width of the rectangle: b
Area = ab
Length has been increased by 10%.
New length = a + 0.1a = 1.1a
New width = b - 0.2b = 0.8b
Area of the new rectangle = 1.1a x 0.8b = 0.88 ab
The area of the new rectangel decreases by 12%. 1.00 - 0.88 = .12 = 12%