It does not appear in https://en.wikipedia.org/wiki/List_of_unsolved_problems_in_m...
Dissect the circle into congruent pieces
such that the center point is in the
interior of one of the pieces.
Summarising, it is possible to dissect a circle into finitely many congruent pieces that do not all touch the center point.
Slightly longer, there are at least two infinite families of solutions:
(a) For every natural number n>1 there are f(n)>0 solutions, with f growing exponentially quickly.
(b) For every natural number n>1 there is an uncountable infinite family.
Thus we have a countable family of solutions, and a countable family of continuous solutions.
So yes, there are solutions that are not all just "slicing a pizza" type solutions.
I didn't mean simple to solve, just lower barrier of entry.
Can be easily generalized to other shapes and more dimensions too.
Simple doesn't mean easy. Factoring a 2048 bit number is very simple and very hard.