Explanation:

- The area of a triangle can be expressed as \( \text{Area} = \frac{1}{2} \times \text{Perimeter} \times \text{inradius} = 15 \, \text{sq cm} \).

- The formula rearranges to \(\text{Perimeter} = \frac{2 \times \text{Area}}{\text{inradius}}\).

- Plug in the values: \(\text{Perimeter} = \frac{2 \times 15}{3} = 10 \, \text{cm}\).

- The perimeter comes out to be 10 cm, which is option 4.

- Option 1: 12 cm - Incorrect, as the calculation gives 10 cm.

- Option 2: 20 cm - Incorrect, as it’s double the result.

- Option 3: 5 cm - Incorrect, as it’s half the result.

- Option 4: 10 cm - Correct, matches the calculation.