It's the equals sign with the ~ above it.
≅
What symbol
think a congruent sign with a slash through it.
= with a ~ on top of it ~ = ≅
= with a ~ on top of it ~ = ≅
it means having the same size and shape
the symbol for congruent is ~ with _ in the same space. (US keyboard does not have a congruent key
"xi" symbol in maths if used mostly in ven diogrammes and is in the top, right hand corner
An ABCDEFGHI.....
The congruence symbol was invented by Gottfried Leibniz.
it is the equal sign = with the symbol ~ over it
copy and paste this ≅
Three vertical parallel lines: |