  3D printing technology can help to visualize proofs in mathematics. In this
document we aim to illustrate how 3D printing can help to visualize concepts
and mathematical proofs. As already known to educators in ancient Greece,
models allow to bring mathematics closer to the public. The new 3D printing
technology makes the realization of such tools more accessible than ever. This
is an updated version of a paper included in book Low-Cost 3D Printing for
science, education and Sustainable Development, ICTP, 2013 edited by Carlo
Fonda Enrique Canessa and Marco Zennaro.
