Join the center C with the points W and Y. From a known theorem, the two angles WOY are twice of the angles WXY and WFY (the central angle is twice of the peripheral angle whose ends sits on the same arc.
then, [tex]2*(8x-8)+2*(14x+12) = 2\pi [/tex] (or 360 if you dont' want to use radians). It's a simple linear equation from now on
