We add a bit to [Which polygons tessellate the hyperbolic plane?](https://mathoverflow.net/questions/398191/which-polygons-tessellate-the-hyperbolic-plane).


**Question:** Are there hyperbolic quadrilaterals with all angles different (not necessarily irrational fractions of π) that tile the hyperbolic plane? What about quads with 3 of the angles equal and 1 different? If the answer to either question is "yes" one could ask for conditions under which tiling happens.



Tiling the hyperbolic plane by non-regular quadrilaterals
Here's a simple solution: start with the equilateral hyperbolic triangle with angles $2\pi/7$, which tiles the hyperbolic plane. Cut it into three congruent quadrilaterals with angles $(2\pi/7, \pi/2+\epsilon, 2\pi/3, \pi/2-\epsilon)$, meeting at the center of the triangle.


