Question

What is the distance between `(6, 8, 2)` and `(4, 3, 1)`?

Answer 1

I assume that you know the distance formula (square root of sum of corresponding coordinates squared)
Well, that formula can actually be EXTENDED to the third dimension. (This is a very powerful thing in future mathematics)
What that means is that instead of the known

`sqrt((a-b)^2 + (c-d)^2`

We can extend this to be
`sqrt((a-b)^2 + (c-d)^2 + (e-f)^2`

This problem is beginning to look a lot easier huh?
We can just plug in the corresponding values into the formula

`sqrt((6-4)^2 + (8-3)^2 + (2-1)^2`

`sqrt(2^2 + 5^2 + 1^2)`

This becomes `sqrt(4 + 25 + 1)`

Which is `sqrt(30)`

This cannot be simplified further, so we are done.