Kite (geometry) across any one of its edges produces another tile; one of them is a right kite, with 60°, 90°, and 120° angles. The tiling that it produces by its reflections is the deltoidal trihexagonal tiling. Among all quadrilaterals, the shape that has the greatest ratio of its perimeter to its diameter is an equidiagonal kite with angles π/3, 5π/12, 5π/6, 5π/12. Its four vertices lie at the three corners and one of the side midpoints of the Reuleaux triangle (above to the right). In non-Euclidean geometry, a Lambert quadrilateral is a right kite with three right angles. A quadrilateral is
Schwarz triangle function general method which works for all right angled triangles for which the two other angles are less than or equal to /4. The previous method for constructing "P", "P", ... is modified by adding an extra triangle each time an angle 3/2 arises at a vertex. The same reasoning applies to prove there is no overlapping and that the tiling covers the hyperbolic upper half plane. On the other hand, the given configuration gives rise to an arithmetic triangle group. These were first studied in . and have given rise to an extensive literature. In 1977 Takeuchi obtained a complete