Geometry

Question Analysis

This question focuses on applying trigonometric functions in a right - triangle. The main task is to determine the correct trigonometric ratio to find the length of side  given an angle and the length of the opposite side.

 

Key Concept Explanation

In a right - triangle:

 

Step - by - Step Solution

We have a right - triangle with an angle of , the side opposite to the  angle has length , and the side we want to find, , is the adjacent side.

Using the tangent function, since , substituting , , and , we get .

 

Option Analysis

A.Cos: Incorrect. Because