Checking to see if 3 points are on the same line

pseudocode
Hossein picture Hossein · Sep 28, 2010 · Viewed 41.1k times · Source

I want to know a piece of a code which can actually tell me if 3 points in a 2D space are on the same line or not. A pseudo-code is also sufficient but Python is better.

Answer

florin picture florin · Sep 28, 2010

You can check if the area of the ABC triangle is 0:

[ Ax * (By - Cy) + Bx * (Cy - Ay) + Cx * (Ay - By) ] / 2

Of course, you don't actually need to divide by 2.

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