Example of a very simple math statement in old literature which is (verbatim) a pain to understand As you know, before symbolic notations were introduced and adopted by the mathematical community, even simple statements were written in a very complicated manner because the writer had (nearly) only words to describe an equation or a result. 
What is an example of a very simple math statement in old literature which is, verbatim, a pain to understand?

The statement of the Pythagorean Theorem always seems to confuse high school students (at least the ones in my classes): "The square of the hypotenuse is equal to the sum of the squares of the other two sides."
