Learning Target 7a

1. Learning Target 7a Circle Terminology Lesson 8-1: Circle Terminology

2. 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

3. Definitions Chord : The segment whose endpoints lie on the circle. A chord that contains the center of the circle. Diameter : A line in the plane of the circle that intersects the circle in exactly one point. Tangent : 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

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

5. 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

6. Polygons A polygon inside the circle whose vertices lie on the circle. Inscribed Polygon: Circumscribed Polygon : A polygon whose sides are tangent to a circle. Lesson 8-1: Circle Terminology

7. B C A O ARCS Arcs : The part or portion on the circle from some point B to C is called an arc. Example: B Semicircle: An arc that is equal to 180°. A C Example: Lesson 8-1: Circle Terminology

8. O Minor Arc & Major Arc A minor arc is an arc that is less than 180° Minor Arc : A minor arc is named using its endpoints with an “arc” above. A Example: Major Arc: A major arc is an arc that is greater than 180°. B B A major arc is named using its endpoints along with another point on the arc (in order). A Example: C Lesson 8-1: Circle Terminology

9. E D A C F Example: ARCS Identify a minor arc, a major arc, and a semicircle, given that is a diameter. Minor Arc: Major Arc: Semicircle: Lesson 8-1: Circle Terminology