For the following proof, consult my picture (I know, you're probably tired of all my pictures, but I like them).
http://newtonmusic4.googlepages.com/AIME082.pngAs can be seen, the shaded area is a parallelogram with area:
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And solving gives us w = 6. Now we can set up a ratio of two similar triangles (since they share similar angles):
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Solving gives us [unparseable or potentially dangerous latex formula], with altitude [unparseable or potentially dangerous latex formula].
Answer: 25 (bubble in 025)