| A | B |
|---|
| circle | set of all points in a plane equidistant from a given point |
| chord | segment whose endpoints are points on a circle |
| diameter | chord that passes through the center of a circle |
| radius | segment whose endpoints are the center of a circle and a point on the circle |
| secant | line that intersects a circle in two points |
| tangent | line that intersects a circle in exactly one point |
| point of tangency | point where a tangent intersects a circle |
| center of a circle | is used to name the circle |
| if diameter is perpendicular to chord | diameter will bisect the chord and its arc |
| minor arc | measure is less than 180 degrees |
| name of minor arc | is determined by its endpoints on the circle |
| length of an arc | found using a proportion |
| semicircle | arc whose central angle measures 180 degrees |
| intercepted arc | arc formed by an inscribed angle |
| measure of an inscribed angle | half the measure of its intercepted arc |
| a tangent is perpendicular to | the radius at the point of tangency |
| inscribed angle | its vertex is on the circle and its sides are chords |
| if a right triangle is inscribed | its hypotenuse is a diameter |
| measure of a major arc | 360 degrees minus the minor arc |
| congruent arcs | arcs with the same measure |
| inscribed polygon | all its vertices lie on the circle |
| name of a major arc | requires three points on the circle |
| tangent segment | one endpoint is point of tangency |
| two points on a circle determine | a major arc and a minor arc |
| congruent circles | have the same radius |
| if polygon is inscribed | the circle is circumscribed |
| measure of a central angle | equals measure of its minor arc |
| arc length | piece of a circumference |
| adjacent arcs | only intersect at their endpoints |
| in an inscribed quadrilateral | opposite angles are supplementary |
