Question

example: railroads crossties i and k are parallel. both crossties are intersected by crosstie h. if m∠1 = 42°, find m∠7.

Explanation:

Step1: Identify corresponding angles

Since cross - ties \(j\) and \(k\) are parallel and intersected by \(l\), \(\angle1\) and \(\angle5\) are corresponding angles. So \(m\angle5=m\angle1 = 42^{\circ}\).

Step2: Identify vertical angles

\(\angle5\) and \(\angle7\) are vertical angles. Vertical angles are congruent. So \(m\angle7=m\angle5\).

Answer:

\(42^{\circ}\)