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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%