Question

what is ( mangle 1 )?( mangle 1 = square^circ )

Explanation:

Step1: Identify corresponding angles

The two lines are parallel (implied by the angle relationships). The angle of \(45^\circ\) in the upper intersection and \(\angle1\) are corresponding angles (or alternate interior angles, depending on the transversal), so they should be equal.

Step2: Determine \(m\angle1\)

Since corresponding angles (or alternate interior angles) are equal when lines are parallel, \(m\angle1 = 45^\circ\).

Answer:

\(45\)