#### Center of a circle equation

## How do you find the center and radius of a circle?

The General Form of the equation of a circle is x^{2} + y^{2} + 2gx +2fy + c = 0. The centre of the circle is (-g, -f) and the radius is √(g^{2} + f^{2} – c). Given a circle in the general form you can complete the square to change it into the standard form. More on this can be found on the Quadratic Equations page Here.

## How do you find the equation of a circle?

The formula for the equation of a circle is (x – h)^{2}+ (y – k)^{2} = r^{2}, where (h, k) represents the coordinates of the center of the circle, and r represents the radius of the circle. If a circle is tangent to the x-axis at (3,0), this means it touches the x-axis at that point.

## Who is the Centre of a circle?

The center of a circle is the point equidistant from the points on the edge. Similarly the center of a sphere is the point equidistant from the points on the surface, and the center of a line segment is the midpoint of the two ends.

## How do you write the standard form of a circle?

The standard form of a circle’s equation is (x-h)² + (y-k)² = r² where (h,k) is the center and r is the radius. To convert an equation to standard form, you can always complete the square separately in x and y.

## What does the equation of a circle mean?

The equation of a circle is a way to express the definition of a circle on the coordinate plane. If the center of the circle is at the origin of the coordinate plane, the equation is where r is the radius. When the center of the circle is at the point (h,k), the equation becomes .