Perimeter = 20.56mm
Given the perimeter, find the diameter
[tex] \pi D[/tex] = 20.56
D = 20.56 ÷[tex] \pi [/tex]
D = 6.54 mm
Perimeter of the Semicircle = half the circle arc + the straight line (Diameter)
Semicircle = 0.5(20.56) + 6.54cm
Semicircle = 16.83mm
