>>14235872A lot of maths wasn't discovered, it was mostly just counting. Also if I remember correctly the Roman elite spoke Greek since they were a load of Greco-boos (like weeboos)
As for engineering and architecture, experience, not sure about engineering but architecture was done by a 7 year apprenticeship so you have enough experience to build stuff on the idea "I've done this a million times before and it worked" (alongside using structures known to work). It actually followed through to modern day somewhat which is why a lot of architects are legally "architectural designers" rather than "architect", since the standard remained despite us now having maths and calculations/simulations to test it
