Renaissance craftsmen, such as painters, were educated in `practical mathematics'. This book tells us the fascintating story of how the artisan tradition made important contributions not only to art but also to `proper' mathematics. Beautiful works of art and famous theorems are linked together in a way that leads to a clearer understanding and greater enjoyment of both. Covering roughly the period from 1300 to 1650, the author shows how, during this time, a new form of geometry - projective geometry - emerged in the context of the artists' mathematics of perspective. Stories of taking measurements while balanced on scaffolding are interspersed with delightful scholarly analyses of the mathematics of great works of art. The text is beautifully illustrated throughout with both photographs and drawings.