Sin α equals half angle α is an acute angle
When α is between 0 and 90, sin α is equal to half, there must be only one solution 30, 150 degrees is not in the range, if there is no range, the answer is 30 + 360K or 150 + 360K, K is an integer
When α is between 0 and 90, sin α is equal to half, there must be only one solution 30, 150 degrees is not in the range, if there is no range, the answer is 30 + 360K or 150 + 360K, K is an integer