Answer:
[tex]\pi r+2r[/tex]
Step-by-step explanation:
[tex]\text{In case of a circle, it's perimeter will be only the length of the curve, which is }\\2\pi r.\text{ Here, }r\text{ is the radius of the circle.}[/tex]
[tex]\text{The semi-circle contains half the length of the curve of the whole circle, i.e. }\pi r,\\\text{and the diameter as its outer boundary. So the perimeter of the semi-circle will}\\\text{be the sum of this curve length and the diameter.}[/tex]
[tex]\therefore\ \text{Perimeter of semi-circle}=\pi r+2r[/tex]
