有没有好办法？

A quatrilateral that has consecutive sides of lengths 70, 90, 130, 110 is inscribed in a circle and also has a circle inscribed in it. The point of tangency of the inscribed circle to the side of length 130 divides that side into segments of lengths x and y. Find |x-y|.

ASHME 1990 problem 28.

Thanks in advance!