Question

given ( m parallel n ), find the value of ( x ).

Explanation:

Step1: Use the property of supplementary angles

When two parallel lines are cut by a transversal, consecutive interior angles are supplementary. That is, the sum of the two angles is \(180^{\circ}\).
So, \(120 + x=180\)

Step2: Solve for \(x\)

Subtract \(120\) from both sides of the equation:
\(x = 180 - 120\)

Answer:

\(60\)