Trigonometry

I am rediscovering Trigonometry, thanks to the book by Prof. Wildberger (Divine Proportions - Rational Trigonometry to Universal Geometry). I always had this problem of understanding angles. Since this was taught at a time when we were asked to "learn" the concepts and "remember" it rather than understand it, I never actually got the concept. Once in college, trigonometry was considered "elementary" and hence was assumed to be known by the students. This created serious problems for me in understanding subjects like Signal Processing, Electromagmetics etc. I came to know about this book from an article in slashdot. The authors idea of "demistifying" trigonometry caught my attention and I immediately ordered the book. I got the book two days back and I am in the process of learning the subject "from scratch". I hope in my second attempt, I will learn it better.