Answer: 4.5pi
This is the same as 9pi/2 or (9/2)pi
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Explanation:
A full circle has area
A = pi*r^2
Since the radius is r = 3, we know that
A = pi*r^2
A = pi*3^2
A = pi*9
A = 9pi
is the area of the full circle with radius 3.
But we have a semicircle here, so we need to cut this area in half
9pi/2 = (9/2)pi = 4.5pi
