The perimeter of the semicircular region is the circumference of the semicircle plus the diameter
- Formula for circumference of a semicircle --> [tex]\frac{1}{2} \pi d = \pi r[/tex]
d: diameter length
r: radius length
6. [tex]Perimeter=\frac{1}{2}\pi d + d= \frac{1}{2} \pi *18+18=9\pi +18 = 46.26cm[/tex]
7. [tex]Perimeter =\frac{1}{2}\pi d+d= \frac{1}{2} \pi *20+20 = 31.4+20=51.4 in[/tex]
8. [tex]Perimeter=\pi r+2r = \pi *4 + 8=20.56mm[/tex]
Hope that helps!
