Geometry · Similarity & Right Triangles
Tangent (Trigonometry)
HSG-SRT.C.8
Definition
In a right triangle, the ratio of the side opposite an angle to the side adjacent.
Examples
- tan(theta) = opposite over adjacent (TOA).
- If the opposite side is 3 and the adjacent side is 4, tan(theta) = 3/4 = 0.75.
Key rule
Tangent always compares the opposite side to the adjacent side, not the hypotenuse.
Memory hook
TOA — Tangent is Opposite over Adjacent.