The area of a regular polygon is half its perimeter multiplied by the distance from its center to its sides, and because the sequence tends to a circle, the corresponding formula–that the area is …

A circle is easy to make: Draw a curve that is radius away from a central point. And so: All points are the same distance from the center. x2 + y2 = 52.

The equation of a circle in general form is, x 2 + y 2 + Dx + Ey + F = 0, where D, E, and F are real numbers. To more easily identify the center and radius of a circle given in general form, we …

Aug 1, 2025 · Use this circle calculator to find the area, circumference, radius or diameter of a circle. Given any one variable A, C, r or d of a circle you can calculate the other three unknowns.

Circle worksheets, videos, tutorials and formulas involving arcs, chords, area, angles, secants and more.

Dec 3, 2025 · A circle is the set of points in a plane that are equidistant from a given point O. The distance r from the center is called the radius, and the point O is called the center.

Oct 29, 2025 · Area of a Circle Formula To find the area of a circle, use the formula A = π • r2, where r is the radius of the circle. If you only know the diameter of the circle, then use the …

The formula for the area of a circle is A = πr 2, where r is the radius of the circle. The unit of area is the square unit, for example, m 2, cm 2, in 2, etc. The area of a circle formula is useful for …

This calculator computes the values of typical circle parameters such as radius, diameter, circumference, and area, using various common units of measurement.

A circle is easy to make: Draw a curve that is radius away from a central point. And so: All points are the same distance from the center.