Insert A4 page in A3 document

Question

I produce exams in A3 format and, when the exam is too long, I want to produce a supplementary page, in A4 format. I use the \newgeometry command of the geometry package, and it's known that this package refuses to pass from A3 to A4 in the same document. So how I can do my purpose ?

I give a simple MWE where I use a boarded minipage to watch up the behaviour when I use \newgeometry.

\documentclass[12pt]{exam}

\usepackage[figuresleft]{rotating}
\usepackage{multicol}
\setlength{\columnsep}{40pt}
\setlength{\columnseprule}{3pt}

\usepackage[a3paper,landscape,margin=2cm,twocolumn]{geometry}
\begin{document}
\pagestyle{empty}
\begin{minipage}{1pt}
\rule{1pt}{4cm}
\end{minipage}
%
\begin{minipage}{15cm}
A first question
\end{minipage}
%
\begin{minipage}{1pt}
\rule{1pt}{4cm}
\end{minipage}

\newpage
\begin{minipage}{1pt}
\rule{1pt}{4cm}
\end{minipage}
%
\begin{minipage}{15cm}
A second question
\end{minipage}
%
\begin{minipage}{1pt}
\rule{1pt}{4cm}
\end{minipage}
\newpage
\newgeometry{a4paper,total={180mm,255mm},includefoot,includehead,centering,twoside,top=10pt}
\begin{minipage}{1pt}
\rule{1pt}{4cm}
\end{minipage}
%
\begin{minipage}{15cm}
A third question
\end{minipage}
%
\begin{minipage}{1pt}
\rule{1pt}{4cm}
\end{minipage}
\end{document}

and it's compilation

One can see the effect on the second page, where the document is clearly in A4 document, but with A3 geometry.

One solution can be to rotate the last page, and playing on dimensions such width, height, top etc to obtain a good rotated centered page, and print it on A4 printer... (Note that that's what I do for A3 pages.. I print it on my A4 printer, and copy it outside "from A4 to A3"..

Answer 1

Some drivers (dvips) do not support changing the paper size in the middle of the document, but others can like pdfTeX or LuaTeX in PDF mode. This is maybe the reason, why package geometry does not allow changing the paper size in \newgeometry.

But the values can be set manually, taken from the options of \newgeometry (do you really want top=10pt, I have replaced it by 21mm for vertical centering)?

The subtraction of 1in is an oddity of TeX, the origin is not the upper left corner, but it is moved horizontally and vertically inside by 1 in.

\newpage
\onecolumn
\setlength{\paperwidth}{210mm}
\setlength{\paperheight}{297mm}
\setlength{\textwidth}{180mm}
\setlength{\textheight}{255mm}
\setlength{\topmargin}{21mm}
\addtolength{\topmargin}{-1in}
\addtolength{\textheight}{-\headheight}
\addtolength{\textheight}{-\headsep}
\addtolength{\textheight}{-\footskip}
\setlength{\oddsidemargin}{\paperwidth}
\addtolength{\oddsidemargin}{-\textwidth}
\setlength{\oddsidemargin}{.5\oddsidemargin}
\addtolength{\oddsidemargin}{-1in}
\setlength{\evensidemargin}{\oddsidemargin}
\setlength{\hsize}{\textwidth}
\setlength{\columnwidth}{\textwidth}
\setlength{\linewidth}{\textwidth}
\setlength{\vsize}{\textheight}
\setlength{\csname @colht\endcsname}{\textheight}
% Driver part (XeLaTeX, pdfTeX or LuaTeX with package `luatex85`)
\setlength{\pdfpagewidth}{\paperwidth}
\setlength{\pdfpageheight}{\paperheight}

Some lines can be saved by using e-TeX's \dimexpr. This is left as exercise for the reader.

PS: Consider generating two documents. This is probably easier to print, less confusion for the PDF viewer/printer.

PPS: Option showframe is a nice feature of geometry to show the page layout, useful for debugging/reviewing the layout settings.