Everyone's heard of Pythagoras, but who's Ptolemy? Learners test Ptolemy's Theorem using a specific cyclic quadrilateral and a ruler in the 22nd installment of a 23-part module. They then work through a proof of the theorem.

In this geometry worksheet, 10th graders write the ratio that represents the sine and cosine of the indicated angle.  The one page worksheet contains two multiple choice questions.  Answers are included.