Angle Measure 2082B4

1. **State the problem:** We have two parallel lines \(M\) and \(N\) cut by a horizontal transversal. We need to find the measure of \(\angle a\). 2. **Identify given information:** \(\angle a\) is below the transversal and to the right of line \(M\). Another angle given is \(55^\circ\), below the transversal and to the left of line \(N\). 3. **Recall the rule:** When two parallel lines are cut by a transversal, alternate interior angles are equal. 4. **Analyze the angles:** The \(55^\circ\) angle and \(\angle a\) are alternate interior angles because they lie between the parallel lines \(M\) and \(N\) on opposite sides of the transversal. 5. **Set up the equation:** $$ m\angle a = 55^\circ $$ 6. **Conclusion:** The measure of \(\angle a\) is \(55^\circ\).