]Use this applet to learn about Reference Angles.[br][br]The default angle is positive. If you would like to investigate negative angles, check the negative angle box on the right.[br][br][b]Remember: The reference angle is created from the terminal side of a given angle and the x-axis. It is always positive.[br][/b][br][br]The given angle is marked in GREEN[br][br]The reference angle is marked in RED