Question

find the measure of angle 6. label optional

Explanation:

Step1: Identify vertical - angle relationship

Angle 3 and the given 80° angle are vertical angles, so $\angle3 = 80^{\circ}$.

Step2: Identify corresponding - angle relationship

Angle 3 and angle 6 are corresponding angles. Since the two lines are parallel (implied by the problem - setup), corresponding angles are equal. So $\angle6=\angle3$.

Answer:

$80^{\circ}$