Geometry

Question Analysis

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

 

Key Concept Explanation

In a right - triangle:

 

Step - by - Step Solution

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

According to the cosine function definition , substituting , , and , we get .

 

Option Analysis

A.Cos