



 
Hi there. If you know the area of the semicircle, you can find the area of the circle it would be in. If you know the area of the circle, the relationship A = π r^{2} gives you the radius. Once you know the radius, you can quickly find the circumference of the circle. Half the circumference of the circle PLUS twice the radius of the circle is the perimeter of the semi circle. Hope this helps,  


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