What about getting the angle from point B to A, then the angle from point B to C, then getting the difference:
on mouseUp put cd fld "A" into pointA put cd fld "B" into pointB -- assumed center of angle put cd fld "C" into pointC -- put fGetAngle(pointB, pointA) into angleA put fGetAngle(pointB, pointC) into angleC if angleC > angleA then put angleC - angleA into cd fld "AngleABC" else put angleA - angleC into cd fld "AngleABC" end if end mouseUp function fGetAngle pPoint1, pPoint2 --angle anticlockwise from X axis return atan2(item 2 of pPoint2 - item 2 of pPoint1,item 1 of pPoint2 - item 1 of pPoint1) * 180 / pi end fGetAngle See atan2 in the dictionary. By the way, this gives 66.209226 for the angle. As a test for known angles, try 250,250 200,200 100,373 This is for angles of 45 degrees and 120 degrees. you should get 75 degrees as your answer. -- View this message in context: http://n4.nabble.com/Deriving-an-angle-from-three-points-tp964930p965051.html Sent from the Revolution - User mailing list archive at Nabble.com. _______________________________________________ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution