# How can I draw a rooted tree structure graph? [duplicate]

I just started doing things with TikZ today and I don't know how to draw a graph which should look like this:

• Welcome to TeX.se. There are literally dozens of questions like this on the site. The forest package is your friend here. Aug 5 at 1:13

As suggested @Alan Munn in his comments, your tree can be simple drawn by use of forest package. For example, the code for the first tree can be:

\documentclass[border=3.141592]{standalone}
\usepackage{forest}
\usetikzlibrary{arrows.meta}

\begin{document}
\begin{forest}
for tree={
edge = {Stealth-},
grow = south
}
[ \^{I}
[2\^{I},
[21\^{I}]
[22\^{I}]
]
[3\^{I},
[31\^{I}]
[32\^{I}]
]
]
\end{forest}
\end{document}


Information about forest you can found in the package documentation.