Question

in the diagram below (mangle7 = 130^{circ}). find the (mangle1) so that (aparallel b).
a. (40^{circ})
b. (130^{circ})
c. (50^{circ})
d. (65^{circ})

Explanation:

Step1: Identify angle - pair relationship

When \(a\parallel b\), \(\angle7\) and \(\angle5\) are vertical angles. Vertical angles are equal. So \(m\angle5 = m\angle7=130^{\circ}\).

Step2: Identify another angle - pair relationship

\(\angle1\) and \(\angle5\) are corresponding angles. When \(a\parallel b\), corresponding angles are equal. So \(m\angle1=m\angle5\).

Answer:

B. \(130^{\circ}\)