What is the reference angle of the angle $\frac{5 \pi}{6} ?$

Step 1 ：The given angle is \( \frac{5 \pi}{6} \) which is in the second quadrant.

Step 2 ：The reference angle in the second quadrant is given by \( \pi - \text{angle} \).

Step 3 ：Calculate \( \pi - \frac{5 \pi}{6} \) to find the reference angle.

Step 4 ：The reference angle of the angle \( \frac{5 \pi}{6} \) is \( \boxed{\frac{\pi}{6}} \).