Answer:
120 degrees, or 2pi/3 radians
Explanation:
Connect this point to the origin. Also, draw a line perpendicular to the y-axis with that point being on such a line. You should have formed a triangle, and a special one at that, known as a 30-60-90 Triangle. If it’s a right triangle, and one side is half of the hypotenuse, it is such a triangle. This means that the angle you formed by connecting the point to the origin is 30 degrees. Along with that, this is a second quadrant angle, so we have to take for account the 90 degree angle in the first quadrant. In total there are 120 degrees.
Good luck on your trigonometry journey!