Below is a list of some of the various symbols you may see in math and through this site and their definitions.

Two line segments are equal in length:

Two angles are equal in measure:

Two lines ore line segments are parallel:

Two lines or line segments are perpendicular:

If two lines or line segments are notated as perpendicular the measure of the angle formed is equal to 90°.

These can be used in conjunction with each other to define the properties of any polygon. For example:

This signifies that line or line segment "X" is parallel to line or line segment "Z":

This is the symbol for the Greek letter delta. In math and science it is often used to represent a "change in " something. For example m is read as a "change in m" where "m" is mass.

This is the Greek letter theta. Often used to represent the measure of an angle: