RAC drawing

[2] Even for planar graphs, allowing some right-angle crossings in a drawing of the graph can significantly improve measures of the drawing quality such as its area or angular resolution.

[3] The complete graph K5 has a RAC drawing with straight edges, but K6 does not.

[1] A complete bipartite graph Ka,b has a RAC drawing with straight edges if and only if either min(a,b) ≤ 2 or a + b ≤ 7.

[11] More specifically, RAC drawing is complete for the existential theory of the reals.

[13] However, in the special case of outer-1-planar graphs, a RAC drawing can be constructed in linear time.