finding angles 0-360

Question

Need help with a math issue: i need to get the true angle from 0 degrees using x and y cordinates im using this at the moment:

Math.atan((x2-x1)/(y1-y2))/(Ma         


        

Answer 1

Also note:

if (y1==y2) {
    if (x1>x2)
        angle = 90;
    else if (x1