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. Learn how to calculate the trig functions (sine, cosine, tangent, cotangent, secant, cosecant) using the unit circle. Learn how to identify the radian measure at various points on the unit circle along with how to count along the unit circle in radian measure in support of calculating the values of the trigonometric functions. Teachers User Instruction & Resource Guide - Includes Recommended books & Trigonometry Websites.