Parallel lines are lines in a plane that never meet and are always the same distance apart.

Intersecting lines are lines that cross each other at one point.

A transversal is a line that intersects two or more lines at distinct points.

A transversal creates corresponding angles, alternate interior angles, and same-side interior angles.

If a transversal intersects two parallel lines, then each pair of corresponding angles is equal.

If a transversal intersects two parallel lines, then each pair of alternate interior angles is equal.

Railroad tracks are an example of parallel lines as they never meet.

Corresponding angles, alternate angles, and same-side interior angles are formed.

A straight angle measures 180 degrees and forms a straight line.

Assuming that angles formed by a transversal are all equal; only certain pairs are equal.

You can use a ruler to check if they are equal distance apart or check the angles formed by a transversal.

Complementary angles are two angles whose sum is 90 degrees.

Supplementary angles are two angles whose sum is 180 degrees.

If two lines have the same slope in coordinate geometry, they are parallel.

An angle is formed by two rays sharing a common endpoint called the vertex.

Interior angles are the angles formed on the inside of parallel lines when cut by a transversal.

Exterior angles are formed on the outside of parallel lines when cut by a transversal.

The measures of angles can indicate whether lines are parallel based on the angle relationships established.

The sum of the angles on the same side of the transversal is supplementary, equal to 180 degrees.