question: public double calcAngleBetweenLines ( Entry start1 , Entry end1 , Entry start2 , Entry end2 ) { double angle1 = calcAngleWithRatios ( start1 , end1 ) ; double angle2 = calcAngleWithRatios ( start2 , end2 ) ; return Math . abs ( angle1 - angle2 ) ; }
target:  Calculates the angle between two given lines. The provided Entry objects mark the starting and end points of the lines.