How to use black down triangle(▼) symbol in LaTeX?

Symbol/Unicode	Black Down Triangle/U+25BC
Type of symbol	Mathematical operator
Package (requirement)	mathabx
Argument	No
Latex command	`\blacktriangledown`
Example	`\blacktriangledown` → ▼

To print the Black Down Triangle symbol in a latex document, you need to use the \blacktriangledown command of the mathabx package.

\documentclass{article}
\usepackage{mathabx}
\begin{document}
   \[ \blacktriangledown\; No\; Smoking \]
   \[ \blacktriangledown\; Use\; Dustbin \]
   \[ \blacktriangledown\; Go\; Ahead \]
\end{document}

Output :