I got stuck solving this following problem:
For which $n\geq 3$ exists a hyperbolic n-gon with geodesic edges and surface area 7?
I know the following things:
the sum of the outer angles of a n-gon is equal to 2$\pi$. And the sum of the inner angle of a n-gon is equal to: $(n-2)\pi$
I also know the Gauss-Bonnet Theorem.
Unfortunately, I don't know how to get further.