How do you find the perimeter of a semi circle when you are only given the diameter, say 24 units?

Hi Lisa,

The perimeter of a circle is π × d where d is the diameter so half of that is ^{1}/_{2}π × d. But If you are going to walk around a semicircle you need to go half way around the circle and then across a diagonal to get back to where you started so the perimeter is ^{1}/_{2}π × d + d.

Penny

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