One could say that trigonometry is the subset of geometry which is specific to the measurement of triangles. Many believe that trig is a very difficult branch of mathematics, but it is actually quite simple. Basic trig principles could easily be learned in one afternoon by anyone proficient in simple algebra, as there are only two laws to be mastered - the Sine Law and the Cosine Law, plus the trig identities of Sine, Cosine, and Tangent (which are merely ratios of the lengths of the sides of triangles). Understanding trig is essential to moving into the more advanced branches of mathematics and also physics.