How to write these two symbols in LaTeX

Question

How to write these two symbols in LaTeX

I know the Latex symbols are $\Delta$ but how to shade the Delta in Latex? Please help.

Answer 1

\documentclass{article}
\usepackage{amssymb}
\usepackage{xcolor}


\begin{document}
    \begin{enumerate}
        \item \(\color{red}\blacktriangle\)
        \item \(\color{red}\blacktriangledown\)
    \end{enumerate}
\end{document}

That would give you

Answer 2

Here is a solution for LuaLaTeX or XeLaTeX:

\documentclass{article}
\tracinglostchars=3
\usepackage[svgnames]{xcolor}
\usepackage{newcomputermodern}

\newcommand\redtriangleup{\textcolor{Red}{\bigblacktriangleup}}
\newcommand\redtriangledown{\textcolor{Red}{\bigblacktriangledown}}

\begin{document}
\[ \redtriangleup\redtriangledown \]
\end{document}

In PDFTeX, load \usepackage{stix} or \usepackage{stix2} instead of \usepackage{newcomputermodern}.

ETA: You can replace \bigblacktriangleup with \blacktriangleup and \bigblacktriangledown with \blacktriangledown as in needle’s answer, while using the same approach. Many more packages support these commands.