Huh?

Via X=Why?, I found an article on how a criminal investigation lab in California is inviting students to come in and showing them that math is useful for solving crimes. (In the CSI way -- figuring out how blood splatters, say -- not in the Numb3rs way.) This is certainly a good thing to do.

But can you make sense of this?

Craig Ogino, the department's crime lab director, started the event by offering a prize of $10 to the student who could use trigonometry to determine the number in gallons of a mixture used to make methamphetamine, based on his sketch.

I'm assuming that trigonometry was actually used for something else -- like, say, the aforementioned blood splattering analysis, seen later in the article -- and that the reporter made a mistake. But I'm not totally sure. Any thoughts?