Batter Hit By Throw while running out of three foot zone.

[urgone]

Not to be picky here...I'm just mathematically curious. So the perfect 90 degree square goes from the apex of home to the back right corner of first to the exact middle of second base to the back left corner of third? Interesting that it is 90 feet from the apex to the BACK of first or third but 90 feet to second is to the MIDDLE of the bag. I'm wondering if that is because when they moved first & third in 1887 they left second where it was.