Here is the actual hyperlink, but without the variables but, I considering it is a circle you can plug the pairs of variables and variables in the correct areas

http://www.davidmaroto.info/Four-Circles

if not... the image is calles Four+Circles.jpg but it has labels and two shaded reagions which are key...

if you know how I could possible insert shapes please let me know how to I can put to diagram on here the correct way...

Answer and explination soon!!!