Lines
Two lines are called this iff they have a common side and their other sides are opposite rays.
Linear pair
An angle that is 90°.
Right
A statement that is assumed to be true or a given
Postulate
If A-B-C, then AB + BC = AC.
The Betweenness of Points Theorem
The scale of measure for a circular protractor.
degrees
This point is called this iff it divides the line segment into two equal segments.
Midpoint of a line segment
An angle is less than 90°.
Acute
The rays in a half-rotation can be numbered from 0 to 180 so that positive number differences measure angles
The Protractor Postulate
"If " OA-OB-OC, then /_AOB + /_BOC = /_AOC
The Betweenness of Rays Theorem
A point is between two other points on the same line iff their coordinate is between the coordinates.
Definition Betweenness of Points
A line is said to do this iff it divides the angle into two equal angles.
Bisects an angle
Two angles are called this iff their sum is 180°
Supplimentary
An angle has exactly one ray that bisects it.
Corollary to the Protactor Postulate
A theorem that can be easily proved as a consequence of a postulate or another theorem.
Corollary
Number or degrees in a semi-circular protractor
180°
A word defined in the dictionary as "coinciding exactly when superimposed."
Congruent
Two angles called this if their sum is 90°
Complementary
The point on a line can be numbered so that positive number differences measure distances.
The Ruler Postulate
The angles in a linear pair are called this.
The rays in a half-rotation can be numbered so that to every ray there corresponds exactly on real number called its ________.
Coordinate
Two lines are called this if they form a right angle
Perpenducular
A line segment has exactly one midpoint.
Corollary to the Ruler Postulate
If the angles in a linear pair are equal, then their sides are said to be ... .
Perpendicular
One real number that corresponds to a point on a number line
Coordinate