This chapter is dedicated to the review of techniques that are used to resolve forms that include trigonometric functions \(\sin {}(x),\cos {}(x)\) and \(\tan {}(x)\) . These three functions are basic building blocks of practically all other trigonometric forms. The objective in this module is to master basic relations among the “special” angles, as well as technique to resolve trigonometric equations and inequalities. Instead of using calculator, the focus is on mastering the use of unit circle, which is essential tool for hand calculations, as well as developing intuition for trigonometric relations (as oppose to memorizing).