I have a sheet of paper with a grid drawn on it, filling the whole paper. This grid has 4 rows and 9 columns, forming 36 congruent rectangles. Also, each of these rectangles is similar in proportion to the whole sheet.

If the sheet is 15 inches wide, how long is it?

In this solution, I am assuming that the width is the shortest side of a rectangle.

Let X be the height of the sheet. Let A be the height of the small rectangles, and B be the width.

4A = 15
A = 3.75

9B = X

3.75/X = B/15
3.75/9B = B/15
56.25 = 9Bē
Bē = 6.25
B = 2.5

X = 22.5 inches

Posted by Iain on 2004-03-22 14:02:26