http://oku.edu.mie-u.ac.jp/~okumura/texfaq/qa/9353.html
を参考にして次のようにしてみました。

\documentclass[b5j]{jsarticle}
\usepackage[debug]{emathPs}
\AtBeginDvi{\special{papersize=B5J}}

%%%%%%%%%%%%DOCUMENT START%%%%%%%%%%%%%%%%
\makeatletter%%%ここから追加
\def\slantbox#1#2{{%
        \newbox\tmp@X
        \setbox\tmp@X\hbox{#2}\edef\tmptok@a{#1}%
        \def\tmptok@b{sl}\ifx\tmptok@a\tmptok@b% θ=atan(1/6)=9.46232°
                \def\@RotDeg{49.7312}\def\sec@Theta{1.01379}%
                \def\csDif@hTheta{.914112}\def\csSum@hTheta{1.07907}%
        \else \def\tmptok@b{it}\ifx\tmptok@a\tmptok@b% θ=atan(1/4)=14.0362°
                \def\@RotDeg{52.0181}\def\sec@Theta{1.03078}%
                \def\csDif@hTheta{.870324}\def\csSum@hTheta{1.11469}%
        \else
                \Mul{#1}{.5}\@hTheta \Add{45}\@hTheta\@RotDeg
                \DegRad\@hTheta\@hTheta
                \Cos\@hTheta\c@hTheta \Sin\@hTheta\s@hTheta
                \Add\c@hTheta\s@hTheta\csSum@hTheta
                \Sub\c@hTheta\s@hTheta\csDif@hTheta
                \Mul\csSum@hTheta\csDif@hTheta\sec@Theta
                \Div{1}\sec@Theta\sec@Theta
        \fi\fi
        \mbox{\rotatebox{-\@RotDeg}{\scalebox{\csDif@hTheta}[\csSum@hTheta]{%
                \rotatebox{45}{\scalebox{1}[\sec@Theta]{%
                        \smash{\makebox[0pt][l]{\usebox{\tmp@X}}}%
                }}%
        }}\phantom{\usebox{\tmp@X}}}%
}}
\def\slbox{\slantbox{sl}}\def\itbox{\slantbox{it}}
\makeatother%ここまで
\begin{document}

\[
\begin{pszahyou*}[ul=2.5mm,borderwidth=3pt]
(0,6.5)(0,6)
\tenretu*{A(0,4);B(0,0);C(4,0);D(4,4)}
\Candk\A{3}\A{30}\Z\E
\Subvec\E\A\P
\Addvec\D\P\F
\Addvec\C\P\G
\Drawlines{\A\B\C\D\A;\A\E\F\G\C;\D\F}
\LandL\A\C\B\D\Q
\Put\Q(0,0){\LARGE \bf 1}
\LandL\D\G\F\C\R
\Put\R(-2pt,0){\rotatebox{30}{\LARGE \bf \slantbox{30}{3}}}%%%%%変更
\LandL\E\D\F\A\S
\Put\S(-5pt,0){\slantbox{60}{\bf 5}}%%%%%%%%%%%%%%%%%%%%%%%%%%%%変更
\end{pszahyou*}
\]
\end{document}

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└◆4364:数字を斜めに? [gaku] 02/18 10:58
　└◆4365:Re:数字を斜めに? [石原　守] 02/18 11:38
　　└◆4366:Re[2]:数字を斜めに? [gaku] 02/18 16:12<-last