Last question i need help with:

THE PAINED PANE:

A triangular piece of glass (labeled XYC) is cut from a rectangular pane (labled ABCD)

What fraction of the area of ABCD is XYC?

What I know:

Points X and Y are the midpoints of the two sides of the rectangular pane.

The diagram/picture: http://www.imagemule.com/uploads/07E8gE.jpg