PARTS OF A CIRCLE Objective I will be

PARTS OF A CIRCLE Objective: I will be able to identify segments and lines related to circles.

AIMS REFERENCE SHEET

DAILY WARM UP WHEN FINISHED WORK ON VOCAB 7

PARTS OF A CIRCLE Chord- Segment whose endpoints are points on a circle Diameter- A chord that passes through the center of the circle Radius- Segment whose endpoints are at the center of the circle and a point on the circle. Secant- A line that intersects a circle in two points Tangent- a line in the same plane of a circle that intersects the circle in exactly one point (point of tangency).

FOLLOW UP Categorize each of the following terms: � Center � Radius � Diameter � Chord � Secant � Tangent � Point Of tangency Points Segments Lines

Example 1 Identify Special Segments and Lines Tell whether the line or segment is best described as a chord, a secant, a tangent, a diameter, or a radius of C. a. AD b. HB c. EG d. JK SOLUTION a. b. c. d. ADis a diameter because it contains the center C and its endpoints are points on the circle HB is a chord because its endpoints are on the circle. EG is a tangent because it intersects the circle exactly in one point. JK is a secant.

FOLLOW UP Name the following Parts Draw each diagram The center of the circle: _____ A point of tangency: _____ Two Radii: _____ Three Chords: _______ A with diameters BC & DE F with tangent GH and secant HJ

Example 2 Name Special Segments, Lines, and Points Identify a chord, a secant, a tangent, a diameter, two radii, the center, and a point of tangency. SOLUTION AB is a chord. HJ FG is a tangent. DE is a diameter. DC is a radius. CE is a radius. C is the center. K is a point of tangency. is a secant.

Example 3 Circles in Coordinate Geometry When a circle lies in a coordinate plane, you can use coordinates to describe particular points of the circle. a. Name the coordinates of the center of each circle. b. Name the coordinates of the intersection of the two circles. c. What is the line that is tangent to both circles? Name the coordinates of the point of tangency. d. What is the length of the diameter of B? What is the length of the radius of A?

Checkpoint 1. Parts of a Circle Identify a chord, a secant, a tangent, a diameter, a radius, the center, and a point of tangency.