The radius of a semicircle is 3 metres. What is the semicircle's perimeter?

To calculate the perimeter of a semicircle, you need to add the circumference of the half circle to the diameter of the circle.

1. First, calculate the diameter of the circle, which is 2 times the radius. In this case, 2 * 3 metres = 6 metres.

2. Then, calculate the circumference of the full circle using the formula 2πr (where r is the radius). In this case, 2 * π * 3 metres = 18.85 metres.

3. Since we only want the circumference of the semicircle (half the circle), we divide this result by 2. So, 18.85 metres / 2 = 9.42 metres.

4. Finally, add the diameter to this result to get the perimeter of the semicircle. So, 9.42 metres + 6 metres = 15.42 metres.

So, the perimeter of the semicircle is approximately 15.42 metres.