1. Lesson 23 Parts of a Circle

2. A circle with the center C is called C
A circle is a set of points in the same plane that are the same distance (equidistant) from a given point called the center of the circle.
A circle with the center C is called C A AE F FG
Radius AE
Diameter D C AC
Radius CE DC
Chord G E
Radius = ½ (diameter)
Diameter = 2(radius)
AC ≅ CE ≅ DC

3. A line in the plane of a circle may or may not intersect the circle.
The point, A, where a circle and a tangent line intersect is the point of tangency A

4. K A
B D
E C F H G I L

5. l Ex. 1 Identify each line or segment that intersects A. Chords:
Tangent:
Radii:
Secant:
Diameter: F A l B E

6. Ex. 2 Using the diagram, find: a) coordinate of centers of circles A and B b) the coordinates of the intersection of circles A and B c) The length of the diameter of each circle d) The length of the radius of each circle