Examine the unit circle. There are two angles on the unit circle for which sin is 1/2. Those are pi/6 and 5pi/6 (30 and 150 degrees). The period for sin is 2pi (360 degrees), so values repeat every 2pi (360 degrees).
The answers are pi/6 +2kpi, 5pi/6 + 2kpi. In degrees it's 30+369k, 150 +360k.