How do you find the center of a circle?

The center of a circle can be determined by finding the point of intersection of the perpendicular bisectors of two of its chords. This is accomplished using a compass and a ruler.

1. Draw two chords

   Draw two chords on the circle using a ruler. For greatest accuracy, avoid chords that are nearly parallel.

2. Construct perpendicular bisectors on the chords.

   Put the compass at one end of the chord. With a compass width that is about two-thirds of the chord, draw arcs above and below it. Without changing the compass width, repeat this on the other end of the chord. Using a ruler, join the two points where the arcs intersect. Repeat this on the other chord.

3. Find the point of intersection of the bisectors

   The point of intersection of the two lines created above is the center of the circle.