Given T = 2π ÷ 3, we want to find the reference number for this value.
Since 2π ÷ 3 lies in the interval [0, 2π), we don't need to find the coterminal angle. Instead, we simply need to identify where 2π ÷ 3 falls in terms of reference angles.
In the unit circle, 2π ÷ 3 corresponds to the reference angle π ÷ 3. Therefore, the reference number for 2π ÷ 3 is 3.
