Gateway to Mathematics Equations of the St. Louis Arch
Eero Saarinen’s Gateway Arch in St. Louis has the form of a catenary, that is, the form taken by a suspended chain. The catenary can be reproduced empirically, but it can also be precisely formulated mathematically. The catenary is similar to the paraboloid in shape, but differs mathematically. Catalan architect Antoni Gaudi used the catenary to great effect in his Church of the Sagrada Familia in Barcelona, but he also used the paraboloid as well.
An arch consists of two weaknesses which, leaning one against the other, make a strength.
Leonardo da Vinci