This series covers essential subjects in Trigonometry and Pre-Calculus with exceptional clarity so that students will feel well prepared to move onto Calculus and Physics. What sets this series apart from other Trigonometry teaching tools is that the concepts are taught entirely through step-by-step example problems of increasing difficulty. It works by introducing each new concept in an easy to understand way and using example problems that are worked out step-by-step and line-by-line to completion. This lesson introduces the important topic of trigonometric angles. Students are taught how to traverse the unit circle in degrees and radians and how to convert between these units of measure. Teachers User Instruction & Resource Guide - Includes Recommended books & Trigonometry Websites.