TikZ – Adding Labels to Sides in a TikZ Figure

Question

I am just getting the hang of tikz, I have the below code for a proof of the Pythagorean theorem

\begin{tikzpicture} [scale=0.50]
\draw (0,0) -- (3,10) -- (13,7) -- (10,-3) -- cycle ;
\draw (3,7) -- (13,7) ;
\draw (3,7) -- (3,10) ;
\draw (10,7) -- (10,-3) ;
\draw (0,0) -- (10,0) ;
\draw (3,0) -- (3,10) ;
\end{tikzpicture}

and it produces the following figure

What I need is the following

I am new to tikz and Latex in general, so I need help. Is there a way to add the side labels for the right triangle as in the labeled figure? I thank all helpers.

Answer 1

\documentclass[12pt]{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture} [scale=0.50]
    \draw (0,0) -- node[left](){c}(3,10) -- (13,7) -- (10,-3) -- cycle ;
    \draw (3,7) -- (13,7) ;
    \draw (3,7) -- (3,10) ;
    \draw (10,7) -- (10,-3) ;
    \draw (0,0) -- node[above, pos=0.2](){b}(10,0) ;
    \draw (3,0) -- node[right](){a}(3,10) ;
\end{tikzpicture}
\end{document}

To understand further

\documentclass[12pt]{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture} [scale=0.50]
    \draw (0,0) -- node[above, pos=1]{c}(3,10) -- (13,7) -- (10,-3) -- cycle ;
    \draw (3,7) -- (13,7) ;
    \draw (3,7) -- (3,10) ;
    \draw (10,7) -- (10,-3) ;
    \draw (0,0) -- node[above, pos=0.5]{b}(10,0) ;
    \draw (3,0) -- node[right=1cm, red, thick, circle, draw]{a}(3,10) ;
\end{tikzpicture}
\end{document}