In math, especially trigonometry we sometimes have difficulty studying the acute triangle which does not. everyone's ideology. Line segment likewise, not everyone is easy to understand. need tutors and extra learning process to understand these formulas. though this is a basic lesson in practical applications of trigonometric formulas.
It makes a student difficulties, plus formula Indices and characters that have a more difficult matter. elementary school students to college is sometimes difficult to determine diameter of circle. need special skills for those who are just starting to learn advanced trigonometry. This sometimes makes students feel the weight and feel lazy to learn trigonometry.