How to draw this diagram?

Question

I don't know how to draw this by latex.

Answer 1

You could use tikz-cd. It bases on TikZ, so you could use TikZ commands and and styles too, but it provides another syntax for such diagrams, arrows and styles, which may be handy with complex diagrams. Your example with tikz-cd:

\documentclass{article}
\usepackage{tikz-cd}
\usetikzlibrary{arrows}
\tikzset{
  commutative diagrams/.cd,
  arrow style=tikz,
  diagrams={>=space}}
\begin{document}
\begin{tikzcd}
               & A \arrow{d}            &              \\
               & B \arrow{dl}\arrow{dr} &              \\
  C \arrow{dr} &                        & D \arrow{dl} \\
               & F                      &              \\
\end{tikzcd}
\end{document}

Answer 2

Have you tried pgf-tikz? Something like this (untested) might work:

\begin {tikzpicture}
\coordinate (a);
\path (a) +(0,-1) coordinate (b);
\path (b) +(-1,-1) coordinate (c);
\path (b) +(1,-1) coordinate (d);
\path (c) +(1,-1) coordinate (f);
\draw (a) node {A} -- 
      (b) node {B} -- 
      (c) node [left]{C} -- 
      (f) node {F} -- 
      (d) node [right]{D} -- 
      (b);
\end {tikzpicture}

You could also look at using the to operation to join the letters ('nodes'). See the tikz tutorial/manual.

Answer 3

You can use Inkscape to do this. Inkscape has the ability to export a combination pdf and tex file. You then use \input{myfigure.tex} and you'll get the image and any text will be the same font as the rest of your document.