what are the area and perimeter and area of half a circle??

Hi Brandon,

The area of a circle is πr^{2} square units where r is the radius of the circle, so the area of half a circle is half of that.

The circumference of a circle is 2 πr units so half way around the circle would be 2 πr/2 = πr units. The perimeter of half a circle however includes the curved part of length π r units and the diameter of length 2 r so the perimeter is πr + 2 r.

Penny

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