Title: READ: Summary of Circle Definitions
Course: Geometry (B)

Circle Definitions

circle: A circle is defined as the set of all points that are the same distance away from a specific point called the center of the circle.

radius: The distance from the center to the circle.

chord: A chord is defined as a line segment starting at one point on the circle and ending at another point on the circle.

diameter: A chord that goes through the center of the circle is called the diameter of the circle.

secant: A secant is a line that cuts through the circle and continues infinitely in both directions.

A tangent line is defined as a line that touches the circle at exactly one point. This point is called the point of tangency.

inscribed polygon: A convex polygon whose vertices all touch a circle is said to be an inscribed polygon.

circumscribed polygon: A convex polygon whose sides all touch a circle is said to be a circumscribed polygon.

Concentric circles are circles of different radii that share the same center point.

arc: A part or portion of a circle.

minor arc: An arc that is less than 180 degrees or half of the circle.

semi-circle: An arc that is exactly 180 degrees or half of the circle.

major arc: An arc that is more than 180 degrees or half of the circle.