Triangle with 3 right angles. Geometry is weird. https://www.quora.com/How-can-I-draw-a-triangle-with-three-90-degree-angles-on-a-sphere https://www.quora.com/

Triangle with 3 right angles. Geometry is weird. https://www.quora.com/How-can-I-draw-a-triangle-with-three-90-degree-angles-on-a-sphere https://www.quora.com/How-can-I-draw-a-triangle-with-three-9... Also, taxicab geometry: https://en.m.wikipedia.org/wiki/Taxicab_geometry https://en.m.wikipedia.org/wiki/Taxicab_geometry