1. The problem asks for the perimeter of a semicircle with radius 3 cm. 2. The perimeter of a semicircle consists of the curved part plus the diameter. 3. The formula for the circumference of a full circle is $$C = 2\pi r$$. 4. The curved part of the semicircle is half the circumference: $$\frac{1}{2} \times 2\pi r = \pi r$$. 5. The diameter is twice the radius: $$d = 2r$$. 6. Therefore, the perimeter $$P$$ of the semicircle is the sum of the curved part and the diameter: $$P = \pi r + 2r$$. 7. Substitute the radius $$r = 3$$ cm: $$P = \pi \times 3 + 2 \times 3 = 3\pi + 6$$. 8. Using $$\pi \approx 3.1416$$, calculate the numerical value: $$P \approx 3 \times 3.1416 + 6 = 9.4248 + 6 = 15.4248$$ cm. 9. The perimeter of the semicircle is approximately $$15.42$$ cm.