Answer
The unknown angle is 48$^{\circ}$.
Work Step by Step
The sum of the angle in a Triangle is 180$^{\circ}$.
Here we will solve for the unknown angle. We will label it $X$.
Therefore:
180$^{\circ}$ = 72$^{\circ}$ + 60$^{\circ}$ + $X$
$X$ = 180$^{\circ}$ - (72$^{\circ}$ + 60$^{\circ}$)
$X$ = 180$^{\circ}$ - (132$^{\circ}$)
$X$ = 48$^{\circ}$