# How To Find The Radius Of A Semicircle?

I'm doing my homework and I need to find out how to find the circumference of a semicircle with a radius of 4
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Anonymous commented
Radius by definition is the length of the line between the circumference and the center of the circle. It is exactly half of the circles diameter.

Since the radius is the measurement from the center or is half the diameter; dividing the circle itself into two would not make any difference to the value of the radius.
So:
If the radius of the circle is 4 cm the radius of the same circle divided into two parts (semi-circle) would also be 4 cm.

The radius of the circle can be found
If the area of the circle is given by using the formula:
Area of a circle= 2πr2
OR
If the circumference is given by using the formula:
Circumference=πr
OR
If the diameter is given:
r= d/2
thanked the writer.
Anonymous commented
Center point to the side is radius, if you divide the circle in half the edge is not the center point so the radius of the full circle would be divided in half as well.