The of an angle is the ratio of the opposite leg length to the adjacent leg length.

a. sine
b. cosine
c. tangent

The tangent of an angle is the ratio of the opposite leg length to the adjacent leg length.

The correct answer would be c, tangent.

To summarize, a tangent is a straight line or plane that touches a curve or curved surface at a point, but if extended does not cross it at that point.