the measure of an angle is $76.3^{\\circ}$. what is the measure of its …

$the measure of an angle is $76.3^{\\circ}$. what is the measure of its …$

the measure of an angle is $76.3^{\circ}$. what is the measure of its supplementary angle? $square^{\circ}$

Supplementary angles sum to $180^\circ$.

Subtract given angle from $180^\circ$:
$180^\circ - 76.3^\circ$

$103.7^\circ$