B...........................
Step-by-step explanation:
Arc length formula is

where x is radinas.
A semi circle has a radian measure of

The radius is half of the diameter, 12 so the radius is

So the arc length is

Area of semi circle is

where r is the radius.



25.3-22.25 = 3.05
What percent of 22.25 is 3.05?
22.25x = 3.05
x = .1370786517
It's marked up 13.7%
It would be 60cm because 40 plus 20 equals 60