Answer: To find the measure of angle 3, we need to use the properties of parallel lines and transversals.
Angle 3 is an alternate interior angle with angle 1 because they are on opposite sides of the transversal line \( \overline{DE} \) and between the parallel lines \( \overline{AB} \) and \( \overline{CD} \).
Since alternate interior angles are congruent when the lines are parallel, we can conclude that:
\[ \text{m}\angle 3 = \text{m}\angle 1 = 50^\circ \]
So, the measure of angle 3 is 50
