My program uses the following method:
   I choose the upper, lower and rightmost points and then sort them
in the order they were visited. Suppose their coordinates are
(x1,y1), (x2,y2), (x3,y3), where 1 was the first visited, 2 - second
and 3 - third.
   Then I put them in a martix
   x1 y1 1
   x2 y2 1
   x3 y3 1
and calculate D=x1*y2*1-x3*y2*1. If D>0, the 3 points are oriented
clockwise. When D<0, then orientation is counterclockwise.
   But what happens when D=0? And why is my method wrong for the
sample input?
   Pls help me!
   Vallery777@yahoo.com