10-1 Circles and Circumference. Circle. The locus of all points in a plane equidistant from a given point called the center . Circles are named by their center point Chord - any segment with endpoints on the circle Diameter - The chord passing through the center of the circle
(where π≈3.14, d is diameter and r is radius)
Example: Find circumference if r = 13 inches
x and y are variables and must ALWAYS be in your answer!
(remember that the formula is x-h and y-k so when naming the center you do the opposite of the equation)
Find the radius by taking the square root of the number after the =
Plot the center and count out for the radius