Question

what is the measure of the unknown angle? n 42° 58° 128° 138° 158° question 6(multiple choice worth 2 points) (14.03 lc) what is the sum of all the angles that are labeled?

Explanation:

Step1: Recall linear - angle property

The two angles \(n\) and \(42^{\circ}\) form a straight - line. The sum of angles on a straight - line is \(180^{\circ}\).
So, \(n + 42^{\circ}=180^{\circ}\).

Step2: Solve for \(n\)

Subtract \(42^{\circ}\) from both sides of the equation: \(n=180^{\circ}-42^{\circ}\).
\(n = 138^{\circ}\).

Answer:

C. \(138^{\circ}\)