Question

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

Step1: Find adjacent interior angle

The 149° angle is supplementary to its adjacent interior angle of the triangle.
$180^\circ - 149^\circ = 31^\circ$

Step2: Find the third interior angle

The triangle's interior angles sum to 180°. We know two angles: 119° and 31°.
$180^\circ - 119^\circ - 31^\circ = 30^\circ$

Step3: Identify $\boldsymbol{m\angle 1}$

The calculated angle is equal to $\angle 1$.

Answer:

$30$