As American as Apple 3.14159

For some reason, driving around this afternoon I was thinking about pie - specifically whether a particular lemon tart could be halved to go in a seven inch tart pan, or whether it would just make sense to make two seven inch tarts, because the recipe calls for one whole lemon, or whether I should just go for the whole thing. And I remembered that once upon a time, I actually made (and saved) a little spreadsheet of the areas of round pans, because I am some kind of closet geek who scales recipes up and down using actual math.

Then I got home and puttered around the intertubes for a bit, and discovered that, according to Niobe and Nora anyway, today is π-day, as in "pi", as in 3.14159..., as in what kind of a weird coincidence is it that I was both thinking about pie, and thinking about the formula to determine the area of a circle which of course involves π?

And I never did make the lemon tart, which probably would have overflowed into the bottom of the oven if I'd done it in seven inch pans, but a recipe for a ten inch tart would halve nicely into a seven inch pan, in case you were wondering.