Final answer:
To determine the quadrant of a radian, use a protractor to measure the angle it makes with the nearest axis. Flip the protractor if the vector is south of the eastward pointing axis.
Step-by-step explanation:
To determine in which quadrant a radian is, you can use a protractor to measure the angle it makes with the nearest horizontal or vertical axis. The easiest way is to measure the angle between the vector and the nearest axis Flip the protractor if the vector is south of the eastward pointing axis.
For example, if the vector is south of the eastward pointing axis, you would flip the protractor upside down and measure the angle between the eastward axis and the vector.