Algebra-2

Question Analysis
This problem assesses the understanding of the cosine function in a right triangle.

Key Concept Explanation
The cosine of an angle in a right triangle is the ratio of the length of the adjacent side to the length of the hypotenuse.

Step-by-step Solution
1. Identify the given values: adjacent side = 12 units, hypotenuse = 15 units.
2. Apply the cosine formula: