JAMB 2000 · UME · Q31

If $P$ and $Q$ are fixed points and $X$ is a point which moves so that $XP = XQ$ , the locus of $X$ is

Worked solution (try it first)

$XP = XQ$ means $X$ is always the same distance from $P$ as from $Q$ .
Such points lie on the line through the mid-point of $PQ$ at right angles to it.
So the locus is the perpendicular bisector of $PQ$ , option D.