One of many is knowing the exact value of pi which is a circle's circumference divided by its diameter.
That's hard to say.
The question is not clear. Hardest, as in the most rigid, is a triangular prism (or tetrahedron). Hardest, to work the geometry of, is probably an irregular blob.
the hardest pitch ever was 106 mph
The hardest math problem ever Also, according to True Jackson V.P, the answer is 16. I paused the screen showing the problem, and x=16
The hardest challenge I've ever faced is life.
Foucault's last conundrum.Fermi's last theromExact value of Pi.
cheats to the hardest game ever
brainteasers
I am pretty sure you can make them as hard as you want - if you have a "hard" problem, you can always find one that is even harder. If this is true, then there is no such thing as a "hardest algebra problem".
Geometry is a VERY broad subject, you need to be more specific.
Diamond. a very hard material that is the hardest substance ever, or at least discover to be the hardest substance on EARTH THAT IS
I had not given a hardest interview like this one you give