Universal definition of vertically mirrored triangles on top of each other

If you want to change the gap, edit the 4pt. If you want to change the overall height, change the {X} to something with a different vertical footprint (possibly a \rule expressed in ex measurement)

\documentclass{article}
\usepackage{scalerel,stackengine,tikz}
\usetikzlibrary{shapes.geometric}
\tikzset{
    uptri/.style={
        draw,
        ultra thick,
        regular polygon,
        regular polygon sides=3,
    }
}
\tikzset{
    dntri/.style={
        draw,
        shape border rotate=180,
        ultra thick,
        regular polygon,
        regular polygon sides=3,
    }
}
\savestack\uptri{\tikz{\node[uptri]{}}}
\savestack\dntri{\tikz{\node[dntri]{}}}
\DeclareRobustCommand\outtri{\mathrel{\scalerel*{%
  \stackengine{4pt}{\dntri}{\uptri}{O}{c}{F}{F}{S}}{X}}}
\DeclareRobustCommand\intri{\mathrel{\scalerel*{%
  \stackengine{4pt}{\uptri}{\dntri}{O}{c}{F}{F}{S}}{X}}}
\begin{document}
$x \outtri Type\qquad x \intri Type$

$\scriptstyle x \outtri Type\qquad x \intri Type$

$\scriptscriptstyle x \outtri Type\qquad x \intri Type$
\end{document}

enter image description here

For example, redefining the overall height to the footprint of x rather than X, by way of

\DeclareRobustCommand\outtri{\mathrel{\scalerel*{%
  \stackengine{4pt}{\dntri}{\uptri}{O}{c}{F}{F}{S}}{x}}}
\DeclareRobustCommand\intri{\mathrel{\scalerel*{%
  \stackengine{4pt}{\uptri}{\dntri}{O}{c}{F}{F}{S}}{x}}}

changes the result thus:

enter image description here

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