How to use congruent(≅) symbol in LaTeX?

In mathematical geometry, congruent symbols are used to compare two triangles. You need to use \cong command for this symbol in latex.

\documentclass{article}
\begin{document}
   \[ \triangle\mathrm{ABC}\cong\triangle\mathrm{PQR} \]
   \[ \overline{\mathrm{BC}}\cong\overline{\mathrm{QR}} \]
   \[ \angle\mathrm{BCA}\cong\angle\mathrm{RQP} \]
\end{document}