Two rectangles are similar. If the height of the first rectangle is 3 inches, and the height of the second rectangle is 9 inches, how much larger is the second rectangle's area?

2 Answers

John McCann answered

Area = width * height

Let us say the similarity is in the width. Call it 5 inches

A = 5 in * 3 in

= 15 in^2

======

A = 5 in * 9 in

= 45 in^2

======As you should have guessed the area of the second rectangle is 3 times as large as the first rectangle.

Tom Jackson answered

If the two rectangles are similar, then the ratio of the side of the 3 inch to the width of the 3 inch must equal the ratio of the side of the 9 inch to the width of the 9 inch

To state that mathematically 3/x = 9/y from which y = 3x for this "family" of similar rectangles.

So if x = 4, y = 12 and the area of one is 12 and the area of the second must be 108.

And if x = 5, y = 15 and the areas are 20 and 135

Two rectangles are similar. If the height of the first rectangle is 3 inches, and the height of the second rectangle is 9 inches, how much larger is the second rectangle's area?

2 Answers

Answer Question