Answer
The angle has a measure of 45$^{\circ}$
Work Step by Step
$\frac{90-a}{180-a}$=$\frac{1}{3}$
270-3a=180-a
2a=90
a=45$^{\circ}$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.