# Finding the Center of a Circle

#### Runner74

##### New member
Hello!

I have an application where I need to find the center of a circle where I am having trouble coming up with a simple way to do this. The diameter of the circle is known and i want to be able to determine the location of it where only a portion of the circle is known. (see the image below) I will know the location of a single point anywhere in the red circumference could anyone help me with this?

#### Country Boy

##### Well-known member
MHB Math Helper
Draw the straight line between two points on the circle. Draw the line bisecting that straight line. Do the same with a second pair of points. The two bisectors intersect at the center of the circle.

#### Runner74

##### New member
Thank you for your reply! I am looking for a formula that i could use to calculate where the center of the circle is based on the known diameter and a single point that resides in the red area. Sorry i should have meant to say in the original post that i was looking for a simple formula.

#### skeeter

##### Well-known member
MHB Math Helper
Thank you for your reply! I am looking for a formula that i could use to calculate where the center of the circle is based on the known diameter and a single point that resides in the red area. Sorry i should have meant to say in the original post that i was looking for a simple formula.
You're going to need at least two distinct points on the red arc of the circle to find its center.