What is the formula for the radius of a semi-circle?
1 Answer
If given the area:
The normal area of a circle is
If given the diameter:
The diameter, like in a normal circle, is just twice the radius.
If given the perimeter:
The perimeter of a semicircle will be one half the circumference of its original circle,
Note: by no means should you commit to memorizing the area or perimeter formulas I've derived here. While they could help you get to answer 30 seconds quicker, they are easily found if you just use logic! This is more an exercise of critical thinking and algebraic manipulation while expanding on your original knowledge of circles.