My interest in the use of primary sources in the teaching of mathematics can be traced back to my own experiences as an undergraduate at a liberal arts college where I was inculcated with an appreciation for making connections between ideas and providing rich layers of context for my understanding of my place in the world. This interest has continued to be fed in my position as a faculty member at another liberal arts college, where I can in turn influence my students in similar ways. In particular, there are few better ways than the study of primary sources in mathematics (1) to give students of the subject with powerful tools for making connections – both within mathematics and in tying mathematics to external areas of study, (2) to motivate the introduction of new mathematical ideas within a framework that is the antithesis of the artificial environment of standard textbooks, and (3) to provide a rich context in which to plant these new ideas by framing them in the same circumstances in which the ideas first developed historically. For TRIUMPHS, I plan to write two sets of classroom projects, one to help students orient themselves in the world of trigonometry by considering the work of Hipparchus, Ptolemy, al-Biruni, and Regiomontanus; and another on the topic of the matrix determinant, in the work of Leibniz, Cramer, Vandermonde, Cauchy, and Gauss.