Question

lines m and n are parallel. find the measure of ∠a. m∠a = ?°

Explanation:

Step1: Use the property of same - side interior angles

When two parallel lines are cut by a transversal, same - side interior angles are supplementary. That is, the sum of same - side interior angles is \(180^{\circ}\).
Let \(\angle a\) and the \(107^{\circ}\) angle be same - side interior angles. So, \(\angle a+107^{\circ}=180^{\circ}\).

Step2: Solve for \(\angle a\)

Subtract \(107^{\circ}\) from both sides of the equation \(\angle a + 107^{\circ}=180^{\circ}\).
\(\angle a=180^{\circ}-107^{\circ}\)
\(\angle a = 73^{\circ}\)

Answer:

\(73\)