# How to draw a triangle with line parallel inside

i need help with this triangle (Image 1), i don't know draw this in tex :c

• Welcome! Although somebody may decide to draw your diagram for you from scratch, it isn't really fair to ask it. What have you tried so far? If you can post some code - ideally in the form of a Minimal Working Example - people will find it easier and more interesting to help (and will therefore be more likely to do so). (Very nearly almost) All questions on this site should include an MWE or an MnWE (if the question is about why it is not-Working an MWE wouldn't be possible or helpful, of course).
– cfr
Commented Jun 11, 2016 at 22:35

\begin{tikzpicture}[x=3cm,y=3cm]
\draw[-,thick] (0,0) -- (2,0) -- (0,1.5);
\node [anchor = east] at (0,0) {O};
\node [anchor = east] at (0,1.5) {L};
\node [anchor = west] at (2,0) {T};
\node [anchor = east] at (0,0.75) {H};
\node [anchor = east] at (1,0.375) {h};
\node [anchor = south] at (0.5,0) {\textit{vt}};
\draw[-,very thick] (0,0) -- (0,1.5);
\draw[-,very thick] (1,0) -- (1,0.75);
\draw[{Bar[width=7mm][sep]Triangle[angle=20:10pt]}-{Triangle[angle=20:10pt][sep]Bar[width=7mm]},thick] (0,-0.25) -- node [anchor=north]{y} (2,-0.25);
\end{tikzpicture}


This requires \usetikzlibrary{arrows.meta}

• You're welcome. I'm just learning tikz myself. Commented Jun 11, 2016 at 23:10
• It works but if you change the size of the triangle you have to make many changes. Have a look at the sections Relative and Incremental Coordinates and Coordinate Calculations and learn how to compute coordinates from other coordinates. Also the 'pos=' option may be useful fro positioning the labels.
– user10274
Commented Jun 12, 2016 at 12:14
– user10274
Commented Jun 13, 2016 at 15:48

And now a solution with pstricks:

\documentclass[x11names, border=3pt]{standalone}
\usepackage{pst-eucl}%,
\usepackage{auto-pst-pdf}

\begin{document}

\begin{pspicture}
\psset{dimen=middle, unit=2, labelsep=0.8ex, linejoin=1, arrowinset=0.12, arrowsize=4pt, tbarsize=10pt, PointSymbol=none, shortput=nab}
\pstTriangle(0,0){O}(0,2){L}(2.5,0){T}
\ncline[offset=-3ex, arrows=|<->|]{O}{T}\lput*{0}{$y$}
\psset{PointName=none, linewidth = 1.5pt, }
\pstMiddleAB{O}{T}{I}
\pstMiddleAB{L}{T}{K}
\ncline{cc-cc}{O}{L}^{$H$}
\ncline{I}{K}^{$h$}
\ncline[linestyle=none]{O}{I}^{$vt$}
\end{pspicture}

\end{document}


and one more TikZ solution:

\documentclass[tikz,border=3mm]{standalone}
\usetikzlibrary{arrows.meta,calc,positioning}

\begin{document}
\begin{tikzpicture}
\coordinate[label=left:$O$] (O);
\coordinate[above=50mm of O, label= left:$L$] (L);
\coordinate[right=50mm of O, label=right:$T$] (T);
%
\draw[thick](O) -- node[left] {$H$} (L)
-- coordinate (h) (T)
-- node[pos=0.75,above]   {$vt$}  cycle;
\draw[thick](h) -- node[left] {$h$}   (h |- O);
\draw[{Bar[width=3mm].Latex[]}-{Latex[]Bar[width=3mm]}]
($(O)-(0,4mm)$) -- node [fill=white] {$y$} ($(T)-(0,4mm)$);
\end{tikzpicture}
\end{document}


Another PSTricks solution:

\documentclass{article}

\usepackage{xfp}

% parameters
\def\height{3}
\def\width{5}
\def\widthSmall{2} % < \width

\begin{document}

\begin{pspicture}(-0.4,-0.4)(\fpeval{\width+0.43},\fpeval{\height+0.43})
\pnodes(0,0){O}(0,\height){L}(\width,0){T}(\widthSmall,0){h}%
(\widthSmall,\fpeval{(1-\widthSmall/\width)*\height}){H}
\pspolygon(L)(T)(O)
\uput[90](L){$L$}
\uput[0](T){$T$}
\uput[225](O){$O$}
\psline(H)(h)
\pcline[offset = -9pt]{|<*->|*}(O)(T)
\ncput*{$y$}
\psset{linestyle = none}
\pcline[offset = 8pt](O)(L)
\ncput{$H$}
\pcline[offset = 6.5pt](O)(h)
\ncput{$vt$}
\pcline[offset = -6.5pt](H)(h)
\ncput{$h$}
\end{pspicture}

\end{document}


All you have to do is change the values of the parameters and the drawing will by adjusted accordingly.