This is a tool to help students envision the meaning of "radian" by thinking in terms of radius-lengths.[br][br]To use: [br]1. Adjust length.[br]2. Adjust radius.[br]3. Guess the radian measure of the arc by envisioning how many radius-lengths the arc is in length.[br]4. Select "Show Radius Scale."[br]5. Move the "unwrap" slider to the right.[br][br]By Ted Coe, tedcoe.com, 2011.