Question

what is the value of a?
a =

Explanation:

Step1: Recall triangle angle sum rule

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

Step2: Identify known angles

Known angles: $90^\circ$, $12^\circ$, and $x$.

Step3: Calculate $x$

$x = 180^\circ - 90^\circ - 12^\circ$
$x = 78^\circ$

Answer:

$78$