How to Draw a Colorized Isoceles Trapezoid within a Pspicture

Question

The pspicture

comes from the code

\documentclass[12pt]{book}
\textheight=8.75in
\usepackage{xcolor,pstricks}

\begin{document}
\thispagestyle{empty}

\begin{pspicture}(-4,-4)(4,8)%
\psframe[fillcolor=blue,fillstyle=solid](-4,-4)(4,8)
%\rput(-4,0){}
\end{pspicture}%
\end{document} 

I would like to add to this picture, a (yellow) isosceles trapezoid with the longer base (8 units) along the entire width of the bottom of the rectangle, and with shorter base exactly 6 units in length. The height of the trapezoid is to be 3 units. In other words, I would like to draw within the pspicture, a trapezoid with vertices (-4,-4), (-3, -1), (3,-1), and (4,-4) and fill it with the color yellow. How may I do this? Is tikz required?

Answer 1

This is vert easy with the \pspolygon* command:

    \documentclass[12pt]{book}
    \textheight=8.75in
    \usepackage{xcolor,pstricks}

    \begin{document}

    \thispagestyle{empty}
    \psset{linejoin=1}
    \begin{pspicture}(-4,-4)(4,8)%
    \psframe[fillcolor=blue,fillstyle=solid](-4,-4)(4,8)
    \pspolygon*[linecolor=yellow](-4,-4)(-3,-1)(3,-1)(4,-4)
    \end{pspicture}%

    \end{document}