Every polygon is either [color=#0000ff]concave [/color]or[color=#0000ff] convex[/color]. [br][br]Here is one way to tell what kind of polygon you have.[br][br]Ask this question. [br][br]Is there a segment with both endpoints [b]inside[/b] the polygon but part of the segment [b]outside[/b] the polygon? [br][br]If the answer is YES then the polygon is CONCAVE.[br][br]If the answer is NO, then the polygon is CONVEX.