Question

The formula used to find the length of a line segment in space.

Answer 1

if youre doing the vocab thing -- Distance

Answer 2

It's the same formula as the one used on Earth. It is based on the Pythagorean theorem.

length = √((∆x)^2 +(∆y)^2 +(∆z)^2)
.. where ∆x, ∆y, ∆z are the differences between the end-point coordinates in the x-, y-, and z-directions, respectively.