Question

find the measure of the missing angle. a 140° answer attempt 1 out of 2 a =

Explanation:

Step1: Recall angle - sum property

The two angles are adjacent and form a straight - line. The sum of adjacent angles on a straight - line is 180°. So, $a + 140^{\circ}=180^{\circ}$.

Step2: Solve for $a$

Subtract 140° from both sides of the equation: $a=180^{\circ}-140^{\circ}$.

Answer:

$40^{\circ}$