What is the arc length of the semicircle?

The arc is equal to the half of circumference.
The formula for circumference is [tex]C=2\pi r=2\pi 11=22\pi\approx69.11[/tex]. Now divide that by 2 and you get [tex]69.11\div2\approx\boxed{34.56}[/tex]
Semicircular arc has a length of approximately 34.56
Hope this helps.
r3t40