Point

An exact location.  It is usually represented as a dot.

Line

is a straight path that extends without end in opposite  directions

Plane

is a perfectly flat surface that extends infinitely in all directions.

Ray

Is a part of a line, It has one endpoint and extends without end in one direction.

Line Segment

Is a part of a line or a ray that extends from one point to another

Congruent

Figures that have the same shape and size.  Line segments that have the same length

Angles

Is formed by two rays with a common endpoint(vertex)

Vertex

The common endpoint of two rays

Right Angles

90 degrees

Acute Angle

Less than 90 degrees

Obtuse Angle

More than 90 degrees but less than 180 degrees

Straight Angle

exactly 180 degrees

Complementary Angles

Two angles that sum measures 90 degrees

Supplementary Angles

Two angles whose sum measures 180 degrees

Perpendicular lines

When lines, segments, or rays intersect and they form a 90 angle

Parallel lines

Lines in the same plane that do not intersect at all.

Skew lines

Lines that do not intersect, and yet they are also not parallel.  They lie in different planes.

Adjacent angles

Have a common vertex and a common side, but no common interior points

Vertical Angles

Are the opposite angles formed by two intersecting lines

Transversal

is a line that intersects two or more lines.

Corresponding angles

Are on the same side of the transversal and are both above or both below the parallel lines.