# How to draw a square and its diagonals with arrows?

I dno't know how to draw arrows as the above figure, and the code I wrote for the four points don't even show up on a result. Why my points don't appear? And what should be added for the arrows?

\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\draw [fill=black](0, 0) circle;
\draw [fill=black](1, 0) circle;
\draw [fill=black](1, -1) circle;
\draw [fill=black](0, -1) circle;
\end{document}

\documentclass{article} \usepackage{tikz} \begin{document} \begin{tikzpicture} \end{document}

• The circles don't show up because their radius is zero. You do know that tikz comes with a very extensive manual full of tutorials and such? May 25, 2016 at 12:29
• @JohnKormylo I just learned a few from YouTube and a pdf file and from this website. Can you give a link for that tutorial? May 25, 2016 at 12:35
• Go to texdoc.net and search for tikz, chances are you already have the manual on your pc May 25, 2016 at 13:05

\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\node[circle, draw=black, fill=black, name=0] at (0,0) {};
\node[xshift=-2mm] at (0.west) {0};

\node[circle, draw=black, fill=black, name=1] at (0,1) {};
\node[xshift=-2mm] at (1.west) {1};

\node[circle, draw=black, fill=black, name=3] at (1,0) {};
\node[xshift=2mm] at (3.east) {3};

\node[circle, minimum width=1pt, draw=black, fill=black, name=2] at (1,1) {};
\node[xshift=2mm] at (2.east) {2};

\draw[->, blue] (0) -- (2);
\draw[->, blue] (0) -- (3);
\draw[->, blue] (0) -- (1);
\draw[->, blue] (1) -- (2);
\draw[->, blue] (1) -- (3);
\draw[->, blue] (2) -- (3);

\end{tikzpicture}
\end{document}

• For smaller dots, inner sep=0pt,minimum size=4pt. Adjust 4pt to ones liking. May 25, 2016 at 16:50

A PSTricks solution:

\documentclass{article}

\usepackage{pst-node}

% parameters
\def\width{3}
\def\height{2}

% size of bounding box

\begin{document}

\begin{pspicture}(-0.27,-0.34)(\Width,\Height)
\pnodes{P}(0,\height)(\width,\height)(\width,0)(0,0)
\psdots(P0)(P1)(P2)(P3)
\psset{arrows = ->, linecolor = cyan!80, nodesep = 1.5pt}
\uput[135](P0){$0$}
\uput[45](P1){$1$}
\uput[315](P2){$2$}
\uput[225](P3){$3$}
\ncline{P0}{P1}
\ncline{P1}{P2}
\ncline{P2}{P3}
\ncline{P0}{P3}
\ncline{P0}{P2}
\ncline{P1}{P3}
\end{pspicture}

\end{document}

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