Anyone here who can help me with this? My sleep-deprived brain is really struggling with it.

I have 3 points: A, B and C

I want to calculate the angle at point B that describes the angle between the two vectors AB and BC but takes the direction into consideration. For example the angle calculated is always anti-clockwise starting from AB and ending at BC.

I have used the cosine law to work out the angle if you treat ABC as a triangle, but I am struggling to know what catch I need to put in to see if I want to use the angle as is or use (360 - angle). Make sense?

Cheers,

Jamie

JimJam•Graphics

http://www.jimjamgraphics.com/