Answer:
The reference angle is π/6 radians
Step-by-step explanation:
The reference angle is the angle that the given angle makes with the x-axis. In order to find a reference angle you have to subtract 2π to your angle (notice that your angle, 13/6 π, is greater than 2π).
13/6 π - 2π = 1/6 π or π/6 radians