Thanks for the clarification. I'm taking in as many resources as I can. I'd imagine that if he goes into engineering or CS, and especially into anything having to do with 3D environments, that cartesian geometry would be more useful.
My son just started Euclidean (planar) geometry, also known as synthetic geometry, and it's quite a departure from what I learned in high school -- analytic geometric (cartesian geometry). He's suffering through it so far but he may ditch the course and go for non-Euclidean geometry instead. Thanks for posting this. It's helpful as I'm trying to determine what's best for his desired career path.
The Zestimate for my house is incredibly close, within $2k of a recent appraisal. There are a lot of comparables in the area, so they have a decent amount of data to work with.
I have a friend who just bought a 3,000sf house on 1/2 of an acre in Lexington, VA for $31k. Zillow has it at $400,000. He's either incredibly lucky and should buy me a beer, or Zillow is the worst. Leaning towards the latter.