Answer: The radius of a circle is the distance from the center of the circle to any point on its edge. It is one of the most important properties of a circle, as it determines its size, area, circumference, and diameter. There are different ways to calculate the radius of a circle, depending on what information you have. Here are some common formulas for finding the radius of a circle:
If you know the diameter of the circle, which is the length of a line that passes through the center and has both endpoints on the edge, then the radius is half of the diameter. In other words, r = d / 2, where r is the radius and d is the diameter.
If you know the circumference of the circle, which is the distance around the edge, then the radius is equal to the circumference divided by 2 times pi. Pi is a special number that is approximately equal to 3.14. In other words, r = c / (2 * pi), where r is the radius, c is the circumference, and pi is 3.14.
If you know the area of the circle, which is the amount of space inside the edge, then the radius is equal to the square root of the area divided by pi. In other words, r = sqrt(A / pi), where r is the radius, A is the area, and pi is 3.14.