The “20 Minutes a Day Ser.: Trigonometry Success in 20 Minutes a Day” by Learningexpress Staff is a textbook focused on improving skills in the subject area of Mathematics, specifically Trigonometry. Published in 2007, this book offers a unique approach to learning by providing bite-sized lessons to be completed in just 20 minutes a day. With 256 pages, this English language publication is part of a series aimed at helping students achieve success in their math studies through focused and efficient learning strategies. Ideal for students looking to improve their understanding of Trigonometry in a concise and effective manner.