Answer:
30.85
Step-by-step explanation:
circumference of a circle = [tex]2\pi r[/tex]
In this case, it's half of that because it's a half circle,
With a diameter of 12, the radius is 6
So, [tex]2\pi 6[/tex] = 37.699 then we diver by 2, so we account for the half circle versus a whole. 37.699/2 = 18.8496.
Then add the 12 that makes bottom line. So 18.496 + 12 = 30.8496
