Question

18 multiple choice 6 points
if $m\angle x = 34^\circ$ and $m\angle z = 26^\circ$, what is $m\angle y$
$m\angle y = 26^\circ$
$m\angle y = 34^\circ$
$m\angle y = 60^\circ$
$m\angle y = 120^\circ$

Explanation:

Step1: Recall triangle angle sum rule

The sum of interior angles in a triangle is $180^\circ$.

Step2: Sum the known angles

$m\angle X + m\angle Z = 34^\circ + 26^\circ = 60^\circ$

Step3: Calculate $\boldsymbol{m\angle Y}$

Subtract the sum from $180^\circ$:
$m\angle Y = 180^\circ - 60^\circ$

Answer:

m∠Y = 120°