Question

1. in the proof, we examine relationships! true false

Explanation:

Step1: Analyze the proof structure

The proof uses properties of parallel lines (corresponding angles) and linear pairs.

Step2: Check the logic

Since \(\angle5\cong\angle1\) (corresponding angles as \(b\parallel c\) and \(a\) is transversal) and \(\angle5\) is supplementary to \(\angle7\) (linear pair), by substitution \(\angle1\) is supplementary to \(\angle7\). The relationships (corresponding angles, linear - pair) are examined.

Answer:

True