How to end paragraph text in an inverted pyramid shape?

Question

In many old books, the final paragraphs of chapters end in an inverted pyramid shape, like this:

I think this is beautiful, so I would like to imitate this for my book. I've found the code for a triangle in this post how to create a triangle with text

\documentclass{article}
\usepackage{microtype,shapepar}

\def\triangleupshape{%
{0}%
{0}b{0}\\%
{8.66}t{-5}{10}\\%
{17.32}t{-10}{20}\\%
{17.32}e{0}%
}    

\begin{document}
\shapepar{\triangleupshape}A ipsum dolor sit amet, consectetuer    adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat. Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat. Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis at vero eros et accumsan et iusto odio dignissim qui blandit praesent luptatum zzril delenit augue duis dolore te feugait nulla facilisi. Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat. \par
\end{document}

Which results in this:

But I'd like it to be inverted and the first part of the paragraph need to be full line width. Only the last few lines should end in an inverted pyramid like in the example above.

Is there a way to do this? Thanks in advance for your help.

Answer 1

Adjust dimensions to your taste:

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{shapepar}
\usepackage{lipsum}
\usepackage{lmodern}
\usepackage{blindtext}
\usepackage{graphicx,stackengine}
\def\asterism{$\vcenter{\hbox{\scalebox{0.7}{\stackon[-0.5pt]{\bfseries*}{\bfseries*~*}}}}$}
\newcommand\myshape{% 
{7}             %line center at x=7
{0}  b{0}\\     % text starts at (0,0)
{0}  t{0}{14}\\ % Line at y=0 starts at x=0 with length 14
{10} t{0}{14}\\ % Line at y=10 starts at x=0 with length 14
{15} t{7}{0}\\  % Line at y=15 starts at x=7 with length 0
{15} e{7}       % text ends at (7,15)
}

\begin{document}
\shapepar{\myshape} \blindtext \blindtext \blindtext \blindtext (\asterism)
\end{document}