So since 9 is your radius because this is half a circle you want to use the equation piR^2 which is pi9^2, by solving this equation you end up with 254.34, which is the area of the semi-circle, now you need to find the area of the box but to solve this you would need the length and width and multiply them together to get the area of the box then subtract that by the area of the semi-circle and you get the shaded region
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