The distance of the point $(1, 2, 3)$ from the $x$-axis is.......

The distance of the point $P(a, b, c)$ from the $x$-axis is

Let $A, B, C$ be the feet of perpendiculars from a point $P$ on the $x, y, z$-axes respectively. Find the coordinates of $A, B$ and $C$ for the following points $P$:
$(i)$ $(3, 4, 2)$
$(ii)$ $(-5, 3, 7)$
$(iii)$ $(4, -3, -5)$

If the centroid of the tetrahedron $OABC$,where $O$ is the origin $(0, 0, 0)$ and $A, B, C$ are given by $(a, 2, 3)$,$(1, b, 2)$,and $(2, 1, c)$ respectively,is $(1, 2, -1)$,then the distance of point $P(a, b, c)$ from the origin is equal to:

If $d_1, d_2, d_3$ are the distances of the point $(1, 2, 3)$ from the $X, Y, Z$-coordinate axes respectively,then $2 d_2^2 + d_3^2 + 1 =$

Find the coordinates of a point on the $y$-axis which is at a distance of $5\sqrt{2}$ from the point $P(3, -2, 5)$.