Enter the circle area, diameter, or circumference and it will solve for the other two
In Euclidean geometry, a circle is a closed plane curve made up of points located at an equal distance from a point called the center. The value of this distance is called the radius of the circle.
The circumference of a circle corresponds to the measurement of its outline, therefore of its perimeter.
To measure the value of the circumference of a circle, it is possible to use a rope and go around it. Then just measure the distance of the winding of the rope using a ruler. However, a more efficient way to measure the circumference of a circle is to use the following formula:
Circumference of a Circle = 2 × π × radius
Or Circumference of a Circle = π × diameter
The area of a circle is the area it occupies.
Unlike the circumference, it is almost impossible to know the area of a circle without using a formula. The area can be calculated only from the value of the radius of the circle.
Area of a Circle = π × radius²
π (Pi), sometimes called Archimedean constant, is a number represented by the Greek letter of the same name in (π). It is the constant ratio of the circumference of a circle to its diameter in a Euclidean plane. It can also be defined as the ratio of the area of a circle to the square of its radius.
- If you know the radius of the circle, double it to get the diameter.
- If you know the circumference of the circle, divide it by π to get the diameter.
- If you know the area of the circle, divide the result by π and find its square root to get the radius; then multiply by 2 to get the diameter.