What is the perimeter of semicircle with radius 3cm

6 + 9.43 = 15.43

3 is the radius so the diameter is 6.

d • pi is the equation for circumference.

6 • pi is approximately 18.85

and because its a semi circle, you divide that by half and get 9.43

then add the diameter and half the circumference which = about 15.43 and thats the perimeter.