Definition and Equation of a Circle

• The set of all Points P having the same distance from the center C

• A closed figure made up of all those points in a plane that are at the same distance from a fixed point

• Point C is called

• Also called fixed point

Common distance from the Center

A chord passing through the center of a circle

A line segment joining two points on a circle

A line intersects two points on a curve

• A line that touches a curve at a point

• A line perpendicular to the center of a circle

• Perimeter of a circle