How do we define circles?

What is a circle?

• the set of all points in a plane at a given distance from a given point
• Given distance is called a RADIUS
• Given point is called a CENTER

Chord

• A line segment that connects two points on a circle



Diameter

• A line segment through the center of a circle with endpoints on the circle.
• Longest chord in the circle

Tangent

• A line that touches a circle in exactly one point.
• Two circles can be tangent at the same line and same point.

Arc

• An arc is a portion of the circumference of a circle.

Resources:

• http://www.mathatube.com/images/circle-lines_1_.gif

Any other lines or segments in a circle?