Fahrenheit is an important and practical measurement system! The 0 point is the freezing point of cheap brandy and the 100 point is the temperature of the armpit of a sweaty Danish guy from the 1700s who just drank a fair amount of said brandy! None of this silly "go to the ocean, distill some water, freeze it and call that 0, boil it and call that 100" nonsense.

And 5' squares are very useful! It's the space in which a short and overly muscled type dressed in silly amounts of metal bits can be expected to swing a kitchen knife around in! If you want a bigger and pointier stick, you need about twice as much space, or 10'. And if you need a measurement of a foot, you just line up the first however many guys out of church heel-to-toe, measure that distance and divide by the number of guys. Easily reproducible anywhere that you have churches, guys, and math!