\documentclass[44pt]{article}
\usepackage[T2A]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[russian]{babel}
\usepackage{hyphenat}
\usepackage{tikz}
\usetikzlibrary{decorations.pathmorphing}
\usetikzlibrary{intersections}
\begin{document}

\begin{tikzpicture}

\begin{tikzpicture}

\draw[step=0.5, color=gray,opacity=0.4] (-2,-2) grid (10,10);

\coordinate (a) at (0,0);
\draw[fill=red]  (0,0) circle (0.1);
\coordinate (b) at (0,4);
\draw[fill=red]  (0,4) circle (0.1);
\coordinate (c) at (4,4);
\draw[fill=red]  (4,4) circle (0.1);
\coordinate (d) at (4,0);
\draw[fill=red]  (4,0) circle (0.1);
\draw (a)--(b)--(c)--(d)--(a);

\coordinate (a) at (5,5);
\draw[fill=red]  (5,5) circle (0.1);
\coordinate (b) at (7,8);
\draw[fill=red]  (7,8) circle (0.1);
\coordinate (c) at (9,5);
\draw[fill=red]  (9,5) circle (0.1);
\draw (a)--(b)--(c)--(a);
\end{tikzpicture}
\end{tikzpicture}
\end{document}