"This book is divided into lessons which are concise but quite comprehensive! Each lesson contains a topic in trig with a good selection of practice problems. Normally trig is taught to students in a way that involves a lot of memorizing and very little intuitiveness, but this book has great explanations that allow me to understand trig laws and graphs easily. Highly recommend! This book makes trig easy to learn, and it's good if you want to learn ahead. Highly recommend! As the author said, the ""best explanation"" possible. He knows how to explain clearly. Highly recommend if you want to learn trig. and get ahead. This book will teach you Trigonometry quickly. Highly recommended."