BA in mathematics from the University of Michigan–Flint. MA in mathematics, MS in computer science, and PhD in geometry from the University of Wisconsin–Madison.
Special interests included the design and analysis of algorithms, software engineering, parallel programming, geometry, and ethnomathematics.
Darrah published a series of papers on the geometry of tilings and is the author of Drawing Pictures with One Line: Exploring Graph Theory (1983). For many years he coached the College’s teams in the annual ACM Computer Programming Competition, including two teams that went to the international finals.