\(\pi\) radians = \(180^\circ\) \(\therefore \frac{\pi}{6}\) radians = \(\frac{180}{6}^\circ = 30^\circ\) Since the sum of the three angles in a triangle is \(180^\circ\), The measure of the third angle = \(180^\circ - (60^\circ + 30^\circ) = 90^\circ\)