Geometry · Similarity & Right Triangles

Sine

HSG-SRT.C.8

Definition

In a right triangle, the ratio of the side opposite an angle to the hypotenuse.

Examples

  • sin(theta) = opposite over hypotenuse (SOH).
  • If the opposite side is 3 and the hypotenuse is 5, sin(theta) = 3/5 = 0.6.

Key rule

Sine always compares the opposite side to the hypotenuse.

Memory hook

SOH — Sine is Opposite over Hypotenuse.