If you look at the unit circle, you'll not only notice that the points have a pattern, the radian measures do as well.

Radian patterns

Take a look at the points on the unit circle that are closest to the x-axis. All of them have a denominator of 6

over 6 - near x-axis

If you look at the measures, they are all
over or under 0, , or It also goes in a pattern of +1, +4, +1, +4 for the numerator values.

over 6 - near x-axis

If you look at the radian measures in the middle of each quadrant, they are all over 4

over 4 - middle radians

Not only that, they all increase by +2 in the numerator each new point

over 4 - middle radians

If you look at all of the radian measurements closest to the y-axis, they are all over 3.

over 3 - near y-axis

The numerator increases by +1, +2, +1

It almost goes in a 1, 2, 3, 4, 5 pattern. You can count the third as the left axis!

over 3 - near y-axis