| A | B |
|---|
| angle | the union of two rays that have the same endpoint |
| bisector | a point line ray or plane which divides a segment angle or figure into two parts of equal measure |
| arc | a part of a circle connecting two points on the circle |
| central angle of a circle | an angle whose vertex is the center of the circle |
| minor arc AB of circle O | the points of circle O that are on or in the interior of angle AOB |
| major arc AB of circle O | the points of circle O that are on or in the exterior of angle AOB |
| degree measure of a minor arc AB of circle O | the measure of the central angle AOB |
| degree measure of a major arc ACB of circle O | 360 minus the measure of arc AB |
| concentric circles | two or more circles that lie in the same plane and have the same center |
| image | the result of applying a transformation to an original figure or preimage |
| preimage | the original figure in a transformation |
| clockwise | the direction in which the hands move on a nondigital clock designated by a negative magnitude |
| counterclockwise | the direction opposite that which the hands move on a nondigital clock designated by a positive magnitude |
| magnitude of rotation | the amount that the preimage is turned about the center of rotation measured in degrees from negative 180 to positive 180 |
| zero angle | an angle whose measure is zero |
| acute angle | an angle whose measure is greater than 0 and less than 90 |
| right angle | an angle whose measure is 90 |
| obtuse angle | an angle whose measure is greater than 90 and less than 180 |
| straight angle | an angle whose measure is 180 |
| complementary angles | two angles the sum of whose measures is 90 |
| supplementary angles | two angle the sum of whose measures is 180 |
| adjacent angles | two nonstraight and nonzero angles with a common side interior to the angle formed by the noncommon sides |
| linear pair | two adjacent angles whose noncommon sides are opposite rays |
| vertical angles | two nonstraight and nonzero angles whose sides form two lines |
| proof argument | a sequence of justified conclusions leading from what is given or known to a final conclusion |
| transversal | a line that intersects two or more lines |
| corresponding angles | a pair of angles in similar locations when two lines are intersected by a transversal |
| slope | in the coordinate plane the change in y values divided by the corresponding change in x values |
| perpendicular | two segments rays or lines such that the lines containing them form a 90 degree angle |
| construction | a drawing which is made using only an unmarked straightedge and compass following certain prescribed rules |
| algorithm | a finite sequence of steps leading to a desired end |
