Geometry

Question Analysis:  
This question tests the classification of a triangle based on side lengths.  
The main focus is verifying whether the triangle follows the Pythagorean Theorem.  

Key Concept Explanation:  
A right triangle satisfies the Pythagorean Theorem:  ，
where c is the longest side (hypotenuse).  

Step-by-Step Solution:  
1. Identify the longest side (hypotenuse): 15 cm.  
2. Apply the Pythagorean Theorem: