Question

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

Explanation:

Step1: Recall angle - sum property

The sum of angles around a point where two lines intersect and a right - angle is involved is 180°.

Step2: Set up the equation

Let the missing angle be $a$. We know that $a + 70^{\circ}+90^{\circ}=180^{\circ}$.

Step3: Solve for $a$

$a=180^{\circ}-(70^{\circ} + 90^{\circ})$. First, calculate the sum inside the parentheses: $70^{\circ}+90^{\circ}=160^{\circ}$. Then, $a = 180^{\circ}-160^{\circ}=20^{\circ}$.

Answer:

$20$