Parallel lines and Transversals

Parallel lines and Transversals

8th grade Thigpen/Neireiter

Parallel Lines

Parallel lines are lines that lie in the same plane that do not intersect.

Transversal

a transversal is a line that passes through two lines in the same plane at two distinct points.

Parallel lines and Transversals

When a TRANSVERSAL intersects a pair of PARALLEL LINES , 8 angles are formed.

These angles have special relationships that you have to remember

The Angles are either Exterior or Interior

-Interior Angles of a Transversal are created where a transversal crosses two parallel lines. Each of the interior angles are INSIDE the parallel lines.

-Exterior Angles are created where a transversal crosses two parallel lines. Each of these angles are OUTSIDE the parallel lines.

Two Types of these Angles are Consecutive and Alternate

Consecutive means on the SAME SIDE of the TRANSVERSAL

Alternate means on OPPOSITE SIDES of the TRANSVERSAL

So the Eight Angles Formed are:

• Consecutive Interior Angles

• Consecutive Exterior Angles

• Alternate Interior Angles

• Alternate Exterior Angles

• ****They can also form Corresponding Angles

Consecutive Interior Angles

Angles on the SAME SIDE of the transversal and INSIDE the parallel lines.

Consecutive Exterior Angles

Angles on the SAME SIDE of the transversal and OUTSIDE the parallel lines.

Alternate Interior Angles

Angles on the OPPOSITE SIDE of the transversal and INSIDE the parallel lines.

Alternate Exterior Angles

Angles on the OPPOSITE SIDE of the transversal and OUTSIDE the parallel lines.

Another Type of angle pairs formed is Corresponding Angles

When two parallel lines are crossed by another line (Transversal), the angles in corresponding positions are called corresponding angles.

Corresponding Angles

Two angles on the SAME SIDE of the transversal that are in corresponding positions one EXTERIOR and one INTERIOR

Multiple Choice

Angle S and A are...

• Alternate Interior Angles
• Consecutive Interior Angles
• Corresponding Angles
• Alternate Exterior Angles

Multiple Choice

Angle C and P are...

• Alternate Interior Angles
• Consecutive Interior Angles
• Corresponding Angles
• Alternate Exterior Angles

Multiple Choice

A line that passes through 2 or more lines is called a ______________.

• transitive
• passer through line
• transversal
• bisector

Multiple Choice

In the diagram, which of the following statements are false?

• ∠1 and ∠4 are vertical angles
• ∠4 and ∠5 are alternate interior angles
• ∠1 and ∠8 are alternate interior angles
• ∠2 and ∠6 are corresponding angles

Multiple Choice

Name the alternate interior angle to angle 3.

• 4
• 5
• 6
• 8

Multiple Choice

What type of angle pair is ∠1 and ∠5?

• alternate interior angles
• corresponding angles
• alternate exterior angles
• vertical angels. 

Multiple Choice

Name the corresponding angle to angle 4.

• angle 8
• angle 6
• angle 2
• angle 5