Windshield wiper

A windshield or windscreen is the front window of a car, a bus, or an aircraft, for example. Wipers are used for removing rain and debris from it. This drawing has been made for students who were calculating the area swept by the blade of the wiper.

Edit and compile if you like:

% Windshield wiper - drawing for calculating the area swept by the blade
% Author: Jimi Oke
\documentclass{article}
\usepackage[margin=2cm]{geometry}
\usepackage{tikz}
\usepackage[active,tightpage]{preview}
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{5pt}
\usetikzlibrary{fadings}
\begin{document}
\begin{tikzpicture}[>=latex]
    \tikzfading[name=fade out, inner color=transparent!0,
         outer color=transparent!100]

    % dimensions and angle
    \draw[|<->|, xshift=0.1cm,yshift=-0.4cm] 
    (15:0) -- (15:6) node[fill=white, midway,sloped] {36 in} ;

    \draw[|<->|, xshift=-0.15cm,yshift=-0.4cm] 
    (155:0) -- (155:2) node[fill=white, midway,sloped] {12 in} ;

    \draw[<-] (15:.6) arc (15:155:.6) ;
    \node at (45:1.1) {$0.8\pi$} ;

    % background/shading
    \fill [gray, path fading=fade out] (-8,-2) rectangle (9,8);

    % sweep area
    \filldraw[gray!50,left color=blue!25, right color=blue!30, middle color=white] 
    (15:2) arc (15:155:2) -- (155:2) -- (155:6) arc (155:15:6) -- (15:2) ;

    \draw[dashed] (15:0) -- (15:2) ;
    \draw[dashed] (155:0) -- (155:2) ;
    
    % wiper blade
    \filldraw(0,0) circle (.08cm) ;
    \filldraw[very thick,black,double distance=1pt] (92:0) -- (92:2.2) ;
    \draw[ultra thick] (90:2) -- (90:6) ;
    \draw[fill=gray!90!blue] (90.5:2.2) -- (94:2.2) -- (91.5:5.5) --
    (90.5:5.5);
    \draw[fill=gray!90!blue]  (90:5.5) -- (91:5.5) -- (90.5:6) --
    (90:6); 
\end{tikzpicture}
\end{document}