1.
A segment line or plane that intersects a segment at its midpoint.
2.
In a right triangle, the sum of the square of the measures of the legs equals the square of the measure of the hypotenuse.
3.
Intersecting lines that form four right angles.
4.
An object consisting of two noncollinear rays with a common endpoint.
5.
If M is the midpoint of AB, then AM = MB.
6.
A boundless n-dimensional set of all points.
7.
Adjective describing a set of points, all of which lie on the same plane
8.
Unit of measure for angles.
9.
A straight path connecting two points that can be extended indefinitely far in either direction.
10.
A set of points that are neither on the sides of the angle nor in the interior of the angle.
11.
If Q is between P and R, then PQ + QR = PR,
orIf PQ + QR = PR, then Q is between P and R.
12.
The first coordinate in an ordered pair.
13.
If R is in the interior of ےPQS, then mےPQR + mےRQS = mےPQS
andIf mےPQR + mےRQS = mےPQS, then R is in the interior of ےPQS.
14.
The points that do not lie on the sides of an angle, but do lie on a line segment that connects the two sides of an angle.
15.
On a measured line, the midpoint of a segment
whose endpoints have the measures a and b is (a + b)/2
In a coordinate plane, the midpoint of a segment
with ends at (x_{1}, y_{1}) and (x_{2}, y_{2}) is at ((x_{1} + x_{2})/2, (y_{1} + y_{2})/2).
16.
A part of a line that extends indefinitely far in one direction.
17.
Preposition to indictate the location of a point collinear with two points found in opposite directions.
18.
A flat surface that extends indefinitely far in all directions.
19.
Collinear rays in opposite directions defined by a common endpoint.
20.
The common endpoint of two rays that define an angle
21.
The commonly used horizontal number line
22.
Two angles, not necessarily adjacent, whose measures have a sum of 180.
23.
An angle whose measure is less than 90 degrees.
24.
The number of square units contained in the interior of a figure.
25.
The name of a point in the coordinate plane.