Problem: Rectangle Detection on Image

  I found the boundary coordinates of all the shapes inside an image,
  and I dont know how I can detect if the Shapes That I have is a rectangles or not.

  to be more specific: Given a sries of pairs (x,y) that represents the boundary
  coordinates of a shape, output one line "Yes" if the shape represent a rectangle
  and "No" if not, prnt a blank line between test cases;)

plz help me with code in c or c++.

Thanx alot, good luck and have fun.

Dummy #1,