Code point
U+25EA
Glyph appearance depends on your fonts.
U+25EA
SoU+25EA SQUARE WITH LOWER RIGHT DIAGONAL HALF BLACK is a Unicode 16.0.0 character in the Other Symbol category. It belongs to the Geometric Shapes block.
Choose the representation you need, then copy its value.
U+25EA
9706
◪
◪
E2 97 AA
25EA
000025EA
%E2%97%AA
\u25EA
\u25EA
\u25EA
\25EA