With the rise of personal desktop 3D printing, a wide spectrum of educational opportunities has become available for educators to leverage this technology in their classrooms. Until recently, the ability to create physical 3D models was well beyond the scope, skill, and budget of many schools. However, since desktop 3D printers have become readily available and increasingly affordable, there has been an explosion in the varieties and quality of 3D printers and software. For the past few years, a physical computing lab at Berry College, HackBerry Lab, has had the opportunity to experiment and share this technology with students, ranging from kindergartners to undergraduates, through lab visits, tours, and even formal classes. Through the engagement of these diverse groups, various elements of the 3D printing process have resonated with students, allowing them to understand traditional concepts in new and tangible ways. With this in mind, the authors began developing a curriculum that could leverage the physical, methodical, and observable nature of 3D printing and apply it to geometric concepts that are abstract and oftentimes difficult for students to grasp. This article discusses the development of a geometry curriculum for students using 3D printing as an instructional tool. Lesson ideas for using 3D design and printing to teach mathematical principles are included.