Proving lines are parallel

Front

What is the definition of parallel lines?

Back

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

Front

What is the Corresponding Angles Postulate?

Back

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

Front

What are Alternate Interior Angles?

Back

Alternate interior angles are pairs of angles that lie between two lines and on opposite sides of a transversal.

Front

What is the Vertical Angles Theorem?

Back

Vertical angles are the angles opposite each other when two lines cross. They are always equal.

Front

If angle 4 is x + 15 and angle 2 is 3x - 5, how do you find the value of x?

Back

Set the equations equal to each other: x + 15 = 3x - 5. Solve for x.

Front

What is the relationship between angles when two lines are parallel and cut by a transversal?

Back

When two lines are parallel, certain angle pairs (corresponding, alternate interior, and same-side interior) have specific relationships (equal or supplementary).

Front

What is the definition of Same-Side Interior Angles?

Back

Same-side interior angles are pairs of angles that lie on the same side of the transversal and between the two lines.

Front

How can you prove that two lines are parallel using angle measures?

Back

If a pair of corresponding angles are equal, or if alternate interior angles are equal, then the lines are parallel.

Front

What is the measure of angle 8 if angle 1 = 135 degrees and lines are parallel?

Back

Angle 8 = 135 degrees, as it is corresponding to angle 1.

Front

What is the significance of angle relationships in proving lines are parallel?

Back

Angle relationships help establish whether lines are parallel based on the properties of angles formed by a transversal.