The celebrated Bolyai-Gerwin theorem states that
"In the Euclidean plane, two simple polygons are scissors-equivalent if and only if they have the same area."
By scissor-equivalent, we meant that one polygon can be dissected by straight lines and the remaining pieces can be placed in a way (no overlapping allowed) that they form the another one.
I am aware that the same holds for the spherical and hyperbolic 2-dimensional geometries. I would like to ask the community for a reference on the proof of Bolyai-Gerwin theorem for the spherical and for the hyperbolic cases. Any reference will be really appreciated.
