Isosceles right triangle glyphs aren’t right-angled

[chris-morgan]

Found in NotoSansMath-Regular.ttf from Arch Linux package noto-fonts 20230401-1.

These four glyphs are supposed to be isosceles triangles with a right angle:

Code point	Name	Sample
U+1F780	BLACK LEFT-POINTING ISOSCELES RIGHT TRIANGLE	🞀
U+1F781	BLACK UP-POINTING ISOSCELES RIGHT TRIANGLE	🞁
U+1F782	BLACK RIGHT-POINTING ISOSCELES RIGHT TRIANGLE	🞂
U+1F783	BLACK DOWN-POINTING ISOSCELES RIGHT TRIANGLE	🞃

But they’ve been drawn in Noto Sans Math with smaller angles, around 53° instead of 90°.

For reference, here’s a proper depiction with a right angle:

Noto Sans Symbols 2 seems to include these glyphs too, but it gets them right.