Trigonometry If you know a side and an angle of a right triangle, then you can find out a lot about the triangle. This is how trigonometry was invented. Trigonometry used to be a separate class in high school. Now we learn part of trig in Geometry, some more in Algebra 2, and more in Pre-Calculus.
When you need to find the angle. 1.Set up the equation 2.Hit the “2nd” key and type sin then the fraction (or decimal some calculators are tempermental about fractions in the trig functions) 3.Make sure to close the parentheses