\documentclass{article}
\usepackage{tikz}
\usepackage{graphicx} 
\usepackage{caption}
\captionsetup{format=hang}
\usepackage[total={13cm,22cm},centering,includehead=true]{geometry}
\usepackage{xepersian} 


\begin{document}


\begin{figure}%
\centering
\parbox{2cm}{%
\begin{tikzpicture}
\begin{scope}[>=latex]
\draw (-0.2,0) node[below,node distance=-0.5cm]{\scalebox{0.8}{$O$}};
\draw (-0.5,0) -- (4,0);
\draw (0,-0.5) -- (0,3);
\draw[->][thick] (0,0) -- (3,0.5)node[right,below]{\scalebox{0.8}{$B$}};
\draw[->][thick] (0,0) -- (1,1.5)node[left,above]{\scalebox{0.8}{$C$}};
\draw[->][thick] (0,0) -- (4,2)node[right]{\scalebox{0.8}{$D=B+C$}};
\draw[densely dashed] (3,0.5) -- (4,2);
\draw[densely dashed] (1,1.5) -- (4,2);
\draw [fill] (0,0) circle [radius=0.03];
\draw [fill] (3,0.5) circle [radius=0.03];
\draw [fill] (1,1.5) circle [radius=0.03];
\draw [fill] (4,2) circle [radius=0.03];
\end{scope}
\end{tikzpicture}
\caption{شکل اول.}%
\label{fig:2figsA}}%
\hskip 5cm
\begin{minipage}{1.2in}%
\centering
\begin{tikzpicture}
\begin{scope}[>=latex]
\draw (-0.2,0) node[below,node distance=-0.5cm]{\scalebox{0.8}{$O$}};
\draw (-0.5,0) -- (4,0);
\draw (0,-0.5) -- (0,3);
\draw[->][thick] (0,0) -- (3,0.5)node[right,below]{\scalebox{0.8}{$B$}};
\draw[->][thick] (0,0) -- (1,1.5)node[left,above]{\scalebox{0.8}{$C$}};
\draw[->][thick] (0,0) -- (4,2)node[right]{\scalebox{0.8}{$D=B+C$}};
\draw[densely dashed] (3,0.5) -- (4,2);
\draw[densely dashed] (1,1.5) -- (4,2);
\draw [fill] (0,0) circle [radius=0.03];
\draw [fill] (3,0.5) circle [radius=0.03];
\draw [fill] (1,1.5) circle [radius=0.03];
\draw [fill] (4,2) circle [radius=0.03];
\end{scope}
\end{tikzpicture}
\caption{شکل دوم.}%
\label{fig:2figsB}%
\end{minipage}%
\end{figure}%

\end{document}