Lesson 23 Parts of a Circle
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
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
K A B D E C F H G I L
l Ex. 1 Identify each line or segment that intersects A. Chords: Tangent: Radii: Secant: Diameter: F A l B E
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