Question

two parallel lines are crossed by a transversal. what is the value of y? y = 40 y = 80 y = 100 y = 120 80° a b c

Explanation:

Step1: Recall angle - relationship

When two parallel lines are crossed by a transversal, corresponding angles are equal and adjacent angles on a straight - line sum to 180°. The 80° angle and the angle adjacent to \(y\) are corresponding angles, so the angle adjacent to \(y\) is 80°.

Step2: Calculate \(y\)

Since the adjacent angle to \(y\) and \(y\) are on a straight - line, we use the formula \(y + 80^{\circ}=180^{\circ}\). Solving for \(y\), we get \(y = 180^{\circ}-80^{\circ}\).

Answer:

\(y = 100\)