Angles in Parallel lines

Parallel Lines and Transversal

Parallel lines are always the same distance apart, they will never intersect.
A transversal is a line that crosses two or more lines.
When a transversal intersects parallel lines, several pairs of congruent and supplementary angles are formed.

Corresponding Angles

Corresponding angles are formed when a transversal passes through two lines.
They are also known as ‘F angles’.
These angles are always in the same place in relation to the parallel lines, e.g., both angles might be in the top right corner of the intersection.
Corresponding angles are always equal.

Alternate Angles

Alternate angles, also known as ‘Z angles’, occur on opposite sides of the transversal, but inside the parallel lines.
Alternate angles are always equal.

Co-Interior Angles

Co-Interior Angles, also known as ‘C angles’, are on the same side of the transversal and inside the parallel lines.
The co-interior angles inside the parallel lines, on the same side of the transversal, are always supplementary. This means their measures add up to 180 degrees.

Vertically Opposite Angles

Vertically opposite angles are formed when two lines intersect.
The angles directly across from each other at the intersection point are always equal.

Exterior Angles

Exterior angles are the angles formed outside the parallel lines, on the opposite sides of the transversal.
The sum of an exterior angle and its corresponding interior angle equals 180 degrees. This is based on the principal that straight line angle measures are always 180 degrees.

Remember, good understanding and practice of these rules are key to improving geometry skills related to angles in parallel lines. Furthermore, always keep the definitions straight and keep practicing problems.