Lesson 8-1: Circle Terminology

Lesson 8-1: Circle Terminology Circle Definition Circle : The set of points coplanar points equidistant from a given point. The given point is called the CENTER of the circle. The distance from the center to the circle is called the RADIUS. Center Radius Lesson 8-1: Circle Terminology

Lesson 8-1: Circle Terminology Definitions Chord : The segment whose endpoints lie on the circle. Diameter : A chord that contains the center of the circle. Tangent : A line in the plane of the circle that intersects the circle in exactly one point. Tangent Point of Tangency : Chord The point where the tangent line intersects the circle. Diameter Secant : A line that contains a chord. Secant Lesson 8-1: Circle Terminology

Lesson 8-1: Circle Terminology Example: In the following figure identify the chords, radii, and diameters. Chords: O D A B F C E Radii: Diameter: Lesson 8-1: Circle Terminology

Lesson 8-1: Circle Terminology Definitions Congruent Circles : Circles that have congruent radii. 2 2 Concentric circles : Circles that lie in the same plane and have the same center. Lesson 8-1: Circle Terminology