To find the measure of the exterior angle \( x \), we can use the relationship between the exterior angle of a triangle and the interior angles. The exterior angle is equal to the sum of the two non-adjacent interior angles.
In this case, you have one exterior angle \( x \) and two interior angles measuring \( 60^\circ \) and \( 45^\circ \). Therefore, the equation can be set up as follows:
\[ x = 60^\circ + 45^\circ \]
Now, calculating the right-hand side:
\[ x = 60^\circ + 45^\circ = 105^\circ \]
Thus, the measure of the exterior angle \( x \) is
\[ \boxed{105^\circ} \]