Arc draws an elliptical arc, with optional style, beginning coordinate at sx,sy, ending coordinate at ex, ey width and height of the arc are specified by ax, ay, the x axis rotation is r if sweep is true, then the arc will be drawn in a "positive-angle" direction (clockwise), if false, the arc is drawn counterclockwise. if large is true, the arc sweep angle is greater than or equal to 180 degrees, otherwise the arc sweep is less than 180 degrees