**Given: **P(1, -1, 0) and Q(2, 1, 2)

**To find:** Distance between given two points

**Formula used: **

The distance between any two points (a, b, c) and (m, n, o) is given by,

\(\sqrt{(a-m)^2+(b-n)^2+(c-0)^2}\)

Therefore,

Distance between (1, -1, 0) and (2, 1, 2) is

= \(\sqrt{(1-2)^2+(-1-1)^2+(0-2)^2}\)

= \(\sqrt{(-1)^2+(-2)^2+(-2)^2}\)

= \(\sqrt{1+4+4}\)

= \(\sqrt{9}\)

= 3

Hence, Distance between P and Q is 3 units