Not sure why you're getting downvoted, this is a legitimate question. However, in this particular case, I think the final sentence of the accepted answer on Physics.SE, namely that
> In this diagram the singularity is a line in spacetime i.e. a one dimensional object in spacetime.
is wrong or at least very misleading – the answer does (correctly) say that asking for the "dimensionality of a singularity […] is a meaningless question because the spacetime geometry is undefined at a singularity".
>A black hole itself (the singularity) is 1 dimensional - a single infinitesimal point.
In Euclidean geometry,
A cube is 3 dimensions.
A plane is 2 dimensions.
A line is 1 dimension.
A point is ...