In a right triangle, the ratio of the length of a given angle's opposite side to the length of the angle's adjacent side. The tangent function is one of the basic functions encountered in trigonometry (the others being the cosine and sine).
Tangent is a high school-level concept that would be first encountered in a trigonometry course. It is listed in the California State Standards for Trigonometry.
| Right Triangle: | A triangle that has a right angle. The Pythagorean Theorem is a relationship among the sides of a right triangle. |
| Trigonometry: | The study of angles and of the angular relationships of planar and three-dimensional figures. |