Why is parallelogram always formed?
- Author:
- Terry Tam
- Topic:
- Parallelogram
ABCD is a quadrilateral, and E, F, G, H are the midpoints of 4 sides of ABCD. Prove that EFGH is a parallelogram. How about ABCD is concave? How about ABCD is crossed? [Varignon's theorem]
(Hint: Consider diagonals)