Joseph O'Rourke is Olin Professor of Computer Science and Professor of Mathematics at Smith College. His research is in discrete and computational geometry, developing algorithms for geometric computations. He has won several awards, including a Guggenheim Fellowship in 1987 and the NSF Director's Award for Distinguished Teaching Scholars in 2001. He was named an ACM Fellow in 2012. He has published more than 165 papers, more than 30 of which were coauthored with undergraduates. He has taught folding and unfolding to students in grade school, middle school, high school, college and graduate school, and to teachers at all educational levels, as well as to researchers in mathematics and computer science. This is his seventh book.