The user-friendly version of this content is available here.

The following content is copyright (c) 2009-2013 by Goods of the Mind, LLC.

This problem trains for: SAT-I, SAT-II, Math Kangaroo 5-6, Math Kangaroo 7-8, Math Kangaroo 9-10.

An equilateral triangle is folded across one if its midlines. What is the ratio between the overlapped area and the area of the figure thus resulted?

In the figure, the overlapped area is shaded. The figure resulted is a trapezoid.

The trapezoid is formed of three triangles congruent to the overlapped area. Therefore,the ratio is 1:3.