Question

The number of rectangles that can be obtained by joining four of the 11 vertices of a 11-sided regular polygon is _________.

Answer 1

Zero, of course! :)

Answer 2

R u sure? Please justify by figure or necessary proof.

Answer 3

http://en.wikipedia.org/wiki/File:Regular_polygon_11.svg

Answer 4

11 vertices creates no symmetry that includes two sides. therefore, connecting two sets of two points can never create two parallel lines. hence, no rectangles!

Answer 5

Thanks a lot

Answer 6

No problem