### Chapter 14 - Trigonometry

This chapter discusses trigonometry, which is the study of triangles.
It contains the following sections:
- section 14.1 - In this section we introduce
the trigonometry of right triangles, then of oblique triangles, and then of vectors
and rotating objects.
- section 14.2 - In this section we
derive and list a set of trigonometric identities and show how they can
be used to simplify trigonometric expressions.
- section 14.3 - In this section we
explain how to solve trigonometric equations. Often trigonometric identities
must be used to solve them.