The world around us exists in 3-dimensional (3D) space. There
are 3 pairs of cardinal directions: left and right, forward and
backward, and up and down. All other directions are simply
combinations of these fundamental directions. Mathematically, these
pairs of directions correspond with three coordinate axes, which
are conventionally labelled X, Y, and Z, respectively. The arrows
in the diagram indicate which directions are considered numerically
positive and which are negative. By convention, right is positive
X, left is negative X, forward is positive Y, backward is negative
Y, and up is positive Z, and down is negative Z. We shall refer to
these directions as +X, -X, +Y, -Y, +Z, and -Z, respectively. The
point where the coordinate axesâ€¦

Victoria Hart, commonly
known as Vi Hart,
is a self-described "recreational mathemusician" who is most known
for her mathematical videos on YouTube.

I copied the previous text from Wikipedia but the next few
lines of text would not be from wikipedia.

Vi Hart one of the well know youtube users with 795,249
subscriptions. She's known for her interesting videos which mainly
contains elements of mathematics. She can sing too!

Though you should not think of her as being deemed as a
mathematician just because of her youtube channel, she has
co-authored several research papers on computational
geometry and mathematics of paper folding .

Her videos always motivated me to stay with maths. From the
first video of Doodling in Math Class (that I saw for â€¦