Answer:
150 °
Step-by-step explanation:
Question says to find about Which of the following angles has a reference angle of 30 °.
We know that reference angle is the smallest angle that the terminal side of a given angle makes with the x-axis.
We will just subtract the given angle 30 ° from 180 ° to get the respective reference angle
180 ° - 30 ° = 150 °
Hence final answer is 150 °
