Im pretty sure this is it-
The measure of your angle is 4.3 radians, according to your statement. This is less than a full circle, which is 2π radians ≈ 6.28 radians.
So, let's look at 4.3/6.28, which turns out to be equal to 0.685; i.e., it is equal to 0.685 of a full circle of 360 degrees; i.e., it is equal to 246.6 degrees. Thus your angle lies in the third quadrant of the (x,y) plane.
