Question

1. find m∠1. 32° 120° 80° 88° 60° 73°

Explanation:

Step1: Find adjacent - interior angle

The exterior angle of 120° and its adjacent - interior angle are supplementary. Let the adjacent - interior angle be $\angle A$. Then $\angle A=180^{\circ}- 120^{\circ}=60^{\circ}$.

Step2: Use angle - sum property of a triangle

The sum of the interior angles of a triangle is 180°. In the triangle, we know one angle is 32° and another is $\angle A = 60^{\circ}$. Let $\angle1=x$. Then $x + 32^{\circ}+60^{\circ}=180^{\circ}$.

Step3: Solve for $\angle1$

$x=180^{\circ}-(32^{\circ}+60^{\circ})=180^{\circ}-92^{\circ}=88^{\circ}$.

Answer:

$88^{\circ}$