Varignon's theorem
- Author:
- Sundararajan
- Topic:
- Area, Geometry, Quadrilaterals
The midpoints of the sides of an arbitrary quadrangle form a parallelogram. If the quadrangle is convex or reentrant, i.e. not a crossing quadrangle, then the area of the parallelogram is half as big as the area of the quadrangle.
http://en.wikipedia.org/wiki/Varignon%27s_theorem