Posted by alex on Wednesday, March 23, 2011 at 10:53am.
The shortest side of a polygon of area 196 sq. in. is 4 in. long. Find the area of a similar polygon whose shortest side is 8 in. long.

geometry  drwls, Wednesday, March 23, 2011 at 11:04am
For similar shapes, the area ratio is proportional to the square of the length ratio for any corresponding sides.
Area(#2)/Area(#1)
= [(short side length#2/short side length#1)]^2 = (8/4)^2 = 4
Thus the larger polygon (#2) has four times that of the smaller polygon #1), or
A2 = 196 * 4 = 784 sq. in.