what is $m\\angle1$?\n$m\\angle1 = \\square^\\circ$\nsubmit

Explanation:

Step1: Find triangle's third angle

Let the third interior angle be $x$. Sum of triangle angles is $180^\circ$. $x = 180^\circ - 52^\circ - 38^\circ = 90^\circ$

Step2: Find supplementary angle $\angle1$

$\angle1$ and $x$ are supplementary (sum to $180^\circ$). $m\angle1 = 180^\circ - 90^\circ$ Alternative Step: Use exterior angle theorem Exterior angle = sum of opposite interior angles. $m\angle1 = 52^\circ + 38^\circ$

Answer:

$90^\circ$