[Tex/LaTex] rectangle with one curved side

pdftextikz-pgf

I would like to create a filled rectangle with one curved side such as
one shown in the picture below:
enter image description here

\begin{tikzpicture}
\draw[red,thick] (0,-3) -- (0,0) -- (3,0) -- (3,-3) edge [bend left] (1,-3);
\draw[red,thick,fill] (1,-3)  edge [bend right] ( 0, -3) ;
\end{tikzpicture}

I am not able to fill it correctly.

Best Answer

You can use tape shape from shapes tikz` library.

\documentclass[tikz]{standalone}
\usetikzlibrary{shapes}
\begin{document}
  \begin{tikzpicture}
\node[tape, draw]{ABCD};
\node[tape, draw, tape bend top=none,tape bend height=2mm,   %% tape bend bottom=none
            tape bend bottom=out and in,fill=red,minimum width=2cm,minimum height=3cm] at (2.5, 0) {};
\end{tikzpicture}
\end{document}

enter image description here

If you want to draw them deliberately, here you go:

\documentclass[tikz]{standalone}
\usetikzlibrary{shapes}
\begin{document}
\begin{tikzpicture}
\draw[red,thick,fill=olive!40] (0,-3) -- (0,0) -- (3,0) -- (3,-3) 
                        to [out=220,in=30]  ( 0, -3) --cycle ;
\end{tikzpicture}
\begin{tikzpicture}
\draw[red,thick,fill=olive] (0,-3) -- (0,0) -- (3,0) -- (3,-3)
                        to [out=220,in=-40]  (1,-3) 
                        to [out=140,in=30] ( 0, -3) --cycle ;
\end{tikzpicture}
\end{document}

enter image description here