The branch of mathematics which studies the relationship between side lengths and angles of triangles is known as trigonometry. This field of study is considered to be the foundation of all applied geometry. The real functions which relate an angle of a right-angled triangle to ratios of two side lengths are called trigonometric functions. They have a wide range of applications in astronomy, music theory, electronics, medical imaging and optics. Astronomy uses the trigonometric technique of triangulation to measure the distance to nearby stars. A few important concepts within trigonometry are triangle identities and trigonometric identities. This book presents the complex subject of trigonometry in the most comprehensible and easy to understand language. It will prove to be immensely beneficial to students and researchers in this field. Coherent flow of topics and extensive use of examples make this book an invaluable source of knowledge.