Question

What are the reference angles for -240, 7pi/5, and 3.85?

Answer 1

Reference angle is the angle u measure from x-axis. For example, if you are given an angle of 380 degrees, you draw the angle. Thats just a line 20 degrees from the x-axis in the 1st quadrant, right?
Now the referece ange is 20 degrees.
Another example, if you are given an angle of 200 degrees, draw the angle. Thats a line in the 3rd quadrant, right? Now, you mesure the angle beween that line and the -ve x-axis( that is the closest x-axis). It is 20 degrees. Reference angle is never negative. Ask me if you are still confused.