| A | B |
|---|
| circle | the set of all points equidistant from a given point |
| center | the point equidistant from every point on the circle |
| radius | the distance from the center to any point on the circle |
| chord | a segment whose endpoints are on the circle |
| diamater | a chord that passes through the center |
| pi (π) | = C/d |
| circumference | = πd |
| arc | part of the circumference of a circl |
| major arc | more than half the circumference of the circle |
| minor arc | less than half the circumference of the circle |
| semi-circle | half the circumference of the circle |
| secant | a line that intersects the circle at exactly two points |
| tangent | a line that intersects the circle at exactly one point |
| adjacent arcs | arcs that have exactly one point in common (an end point) |
| central angle | an angle whose vertex is the center of the circle |
| inscribed angle | an angle whose vertex is on the circumference of the circle |
| concentric circles | circles that have the same center but different radii |
| congruent circles | circles with the same radii |
| point of tangency | the point where the tangent line and circle intersect |
| interior of the circle | the points inside the circle |
| exterior of the circle | the points outside the circle |
