Final answer:
The terminal side of an angle can be determined by considering its sign and placement in the coordinate plane based on the quadrant.
Step-by-step explanation:
To determine the quadrant in which the terminal side of an angle falls, consider the given angle and its sign (positive or negative). Here are the quadrant placements for the given angles:
- A) 210°: This angle is positive, and 210° terminates in quadrant III.
- B) -150°: This angle is negative, and -150° terminates in quadrant II.
- C) 390°: This angle is positive, and 390° terminates in quadrant IV.