Find the distance from the origin to the point $(6, 6, 7)$.

In the figure,if $P$ is $(2, 4, 5)$,find the coordinates of $F$.

If $P(5, 4, a)$ and $Q(-1, 2, -2)$ are two points such that $PQ = 7$,then the values of $a$ are ..........

$A$ point lies in the $yz$-plane,and the sum of its coordinates is $3$. If the distance of the point from the $xz$-plane is twice the distance of the point from the $xy$-plane,find its coordinates.

If the extremities of a diagonal of a square are $(1, -2, 3)$ and $(2, -3, 5)$,then the length of its side is

If the extremities of a diagonal of a square are $(1, 2, 3)$ and $(2, -3, 5)$, then its side is of length