Solve the geometry problem shown in this image.

Steps:

1. Identify the given sides of the right-angled triangle. The two legs are 3 cm and 4 cm.
2. Apply the Pythagorean theorem, which states that for a right-angled triangle with legs 'a' and 'b' and hypotenuse 'c', a² + b² = c².
3. Substitute the given values into the theorem: 3² + 4² = c²
4. Calculate the squares: 9 + 16 = c²
5. Add the values: 25 = c²
6. Take the square root of both sides to find 'c': c = √25 c = 5 cm