Point E lies on segment AB, and point C lies on segment FG. The area of parallelogram ABCD is 20 square units. What’s the area of parallelogram EFGD?
Source: Alfred S. Posamentier, Math Wonders to Inspire Teachers and Students, 2003.
Triangle CDE is half of parallelogram ABCD because they have a common side and the third point is on the opposite side.
Triangle CDE is also half of parallelogram EFGD because they have a common side and the third point is on the opposite side.
Therefore the parallelograms have the same area.
Posted by Jer
on 2016-09-19 13:18:20