All of that perhaps is true, but the fact remains, he used both algebra and trig, though he didn't know it by that name.
Likely, he picked up 'rules of thumb' which were essentially the same thing.
My Uncle Jack graduated from the same institution - University of Hard Knocks.
Likely, he picked up 'rules of thumb' which were essentially the same thing. >>>>>>>>>>>
Mainly, he learned to understand a framing square! I heard him tell someone once about how he struggled with it until he understood it, it seems that others had tried to teach it to him unsuccessfully but he finally sat down all alone one day and puzzled it out on his own.