Answer:
15√2
Step-by-step explanation:
They tell us the triangle was made from a 15cm sided square sheet. These sides will be our A and B in the pythagorean theorem:
C² = A² + B², C is the hypotenuse. Solving:
C² = 15cm² + 15cm² = √(15cm)²+(15cm)²
C = 15√2