#### Answer

The difference between the measure of its supplement and the measure of its complement is $90^{\circ}$

#### Work Step by Step

Let $A$ be the supplement of $x$:
$A = 180^{\circ}-x$
Let $B$ be the complement of $x$:
$B = 90^{\circ}-x$
We can find the difference between $A$ and $B$:
$A-B = (180^{\circ}-x)-(90^{\circ}-x)$
$A-B = 180^{\circ}-x-90^{\circ}+x$
$A-B = 180^{\circ}-90^{\circ}$
$A-B = 90^{\circ}$
The difference between the measure of its supplement and the measure of its complement is $90^{\circ}$