Question

what is m∠1? m∠1 =

Explanation:

Step1: Use exterior - angle property

The exterior - angle of a triangle is equal to the sum of the two non - adjacent interior angles. Let the exterior angle be $143^{\circ}$, and the two non - adjacent interior angles be $\angle1$ and $52^{\circ}$. So, $143^{\circ}=\angle1 + 52^{\circ}$.

Step2: Solve for $\angle1$

We can rewrite the equation as $\angle1=143^{\circ}-52^{\circ}$.
$143 - 52=91$

Answer:

$91$