As bmv already answered, it's not possible to rotate a pattern, but it's not too difficult to define new rotated patterns.
Information about it can be found in section 104 Patterns and already defined styles can be found in file pgflibrarypatterns.code.tex
.
Based on checkerboard light gray
and horizontal lines light gray
I've defined rotated checkerboard light gray
and vertical lines light gray
. The code can be found in following lines:
\documentclass[margin=2pt]{standalone}
\usepackage{tikz,siunitx}
\usetikzlibrary{%
calc,
intersections,
patterns}
\pgfdeclarepatterninherentlycolored{rotated checkerboard light gray}
{\pgfpointorigin}{\pgfqpoint{4mm}{4mm}}{\pgfqpoint{4mm}{4mm}}%
{
\pgfsetfillcolor{black!10}
\pgfpathrectangle{\pgfpointorigin}{\pgfqpoint{4.1mm}{4.1mm}}% make
% slightly larger to ensure that tiles
% are really solid
\pgfusepath{fill}
\pgfsetfillcolor{black!20}
\pgfpathmoveto{\pgfqpoint{0mm}{2mm}}
\pgfpathlineto{\pgfqpoint{2mm}{4mm}}
\pgfpathlineto{\pgfqpoint{4mm}{2mm}}
\pgfpathlineto{\pgfqpoint{2mm}{0mm}}
\pgfpathlineto{\pgfqpoint{0mm}{2mm}}
\pgfusepath{fill}
}
\pgfdeclarepatterninherentlycolored{vertical lines light gray}
{\pgfpointorigin}{\pgfpoint{4pt}{100pt}}
{\pgfpoint{4pt}{100pt}}
{
\pgfsetfillcolor{black!10}
\pgfpathrectangle{\pgfpointorigin}{\pgfpoint{2.5pt}{100pt}}
\pgfusepath{fill}
\pgfsetfillcolor{black!15}
\pgfpathrectangle{\pgfpoint{2pt}{0pt}}{\pgfpoint{2.5pt}{100pt}}
\pgfusepath{fill}
}
\begin{document}
\hfill\begin{tikzpicture}[%
every node/.style={font=\small}]
\def\X{3.5}
\coordinate (A) at (90:\X) ;
\coordinate (B) at (210:\X) ;
\coordinate (C) at (-30:\X) ;
\coordinate (I) at ($(A)!.5!(B)$) ;
\coordinate (J) at ($(A)!.5!(C)$) ;
\coordinate (K) at ($(C)!.5!(B)$) ;
\coordinate (E) at ($(B)!.5!(K)$) ;
\coordinate (F) at ($(C)!.5!(K)$) ;
\coordinate (N) at ($(E)!(F)!(J)$) ;
\coordinate (M) at ($(E)!(I)!(J)$) ;
\coordinate (N') at ($(N)!2!(J)$) ;
\coordinate (F') at ($(F)!2!(J)$) ;
\coordinate (M') at ($(M)!2!(I)$) ;
\coordinate (E') at ($(E)!2!(I)$) ;
\begin{scope}
\clip (0,0) rectangle (0,0) ;
\draw[name path=P1] (N')--($(N')!3!(F')$) ;
\draw[name path=P2] (M')--($(M')!3!(E')$) ;
\path[name intersections={%
of= P1 and P2, % nom des paths
by=D, % nom des points
sort by=P1, % suivant le path
total=\t}] % nb de points
\pgfextra{\xdef\InterNb{\t} } ;
\end{scope}
\fill[pattern=rotated checkerboard light gray] (M)--(I)--(A)--(J)--cycle ;
\path[pattern=horizontal lines light blue] (E)--(M)--(I)--(B)--cycle;
\path[pattern=horizontal lines light blue] (E')--(M')--(I)--(A)--cycle;
\path[pattern=vertical lines light gray] (F)--(N)--(J)--(C)--cycle;
\path[pattern=horizontal lines light gray] (F')--(N')--(J)--(A)--cycle;
%\draw pic[%
% "\SI{71}{\degree}",
% draw,
% fill=blue!15,
% angle eccentricity=1.4,
% angle radius=.7cm
% ] {angle=B--I--M} ;
%\draw pic[%
% "\SI{131}{\degree}",
% draw,
% fill=blue!15,
% angle eccentricity=1.5,
% angle radius=.6cm
% ] {angle=C--F--N} ;
%\draw pic[%
% "\SI{101}{\degree}",
% draw,
% fill=blue!15,
% angle eccentricity=1.7,
% angle radius=.6cm
% ] {angle=A--J--E} ;
\draw (A)--(B)--(C)--cycle ;
\draw (J)--(E) ;
\draw (I)--(M) ;
\draw (F)--(N) ;
\draw (F')--(E') ;
\draw[thick] (M)--(N')--(D)--(M')--cycle ;
\foreach \Coor/\Text/\Pos in
{A/$A$/90,
B/$B$/-135,
C/$C$/-45,
E/$E$/-90,
F/$F$/-90,
I/$I$/180,
J/$J$/0,
M/$M$/-80,
N/$N$/100%
} {%
% \path (\Coor) pic {Cross={2 and black}} ;
%\node[small dot] at (\Coor) {} ;
\node[shift=(\Pos:8pt),anchor=center] at (\Coor) {\Text} ;
}
\end{tikzpicture}\hfill\strut
\end{document}

Update
With patterns.meta
library is possible to rotate a pattern and also define new patterns with TiKZ syntax instead of only pgf syntax.
Following code shows the previous answer adapted to patterns.meta
library. Main changes are the use of parametric Lines
pattern and an example of tikzdeclarepattern
applied to the rotated checkboard
.
\documentclass[margin=2pt]{standalone}
\usepackage{tikz,siunitx}
\usetikzlibrary{%
calc,
intersections,
patterns.meta}
\tikzdeclarepattern{
name = rotated checkboard,
type=uncolored,
parameters={\squaresize, \boardangle},
bottom left={(-.1pt,-.1pt)},
top right={(\squaresize+.1pt,\squaresize+.1pt)},
tile size={(\squaresize,\squaresize)},
tile transformation={rotate=\boardangle},
defaults={
tile size/.store in=\squaresize, tile size=10pt,
rotate/.store in=\boardangle, rotate=0
},
code={
\tikzset{x=1pt,y=1pt}
\fill (0,0) rectangle (\squaresize/2,\squaresize/2);
\fill (\squaresize/2,\squaresize/2) rectangle (\squaresize,\squaresize);
}
}
\begin{document}
\hfill\begin{tikzpicture}[%
every node/.style={font=\small}]
\def\X{3.5}
\coordinate (A) at (90:\X) ;
\coordinate (B) at (210:\X) ;
\coordinate (C) at (-30:\X) ;
\coordinate (I) at ($(A)!.5!(B)$) ;
\coordinate (J) at ($(A)!.5!(C)$) ;
\coordinate (K) at ($(C)!.5!(B)$) ;
\coordinate (E) at ($(B)!.5!(K)$) ;
\coordinate (F) at ($(C)!.5!(K)$) ;
\coordinate (N) at ($(E)!(F)!(J)$) ;
\coordinate (M) at ($(E)!(I)!(J)$) ;
\coordinate (N') at ($(N)!2!(J)$) ;
\coordinate (F') at ($(F)!2!(J)$) ;
\coordinate (M') at ($(M)!2!(I)$) ;
\coordinate (E') at ($(E)!2!(I)$) ;
\begin{scope}
\clip (0,0) rectangle (0,0) ;
\draw[name path=P1] (N')--($(N')!3!(F')$) ;
\draw[name path=P2] (M')--($(M')!3!(E')$) ;
\path[name intersections={%
of= P1 and P2, % nom des paths
by=D, % nom des points
sort by=P1, % suivant le path
total=\t}] % nb de points
\pgfextra{\xdef\InterNb{\t} } ;
\end{scope}
\fill[fill=orange!10, postaction={pattern={rotated checkboard[rotate=30, tile size=2mm]}, pattern color=orange}] (M)--(I)--(A)--(J)--cycle ;
\path[fill=cyan!20, postaction={pattern={Lines[angle=20, line width=2pt, distance=5pt]}, pattern color=cyan!70!black}] (E)--(M)--(I)--(B)--cycle;
\path[fill=red!30, postaction={pattern={Lines[angle=-35, line width=2pt, distance=6pt]}, pattern color=red!70!black}] (E')--(M')--(I)--(A)--cycle;
\path[fill=cyan!20, postaction={pattern={Lines[angle=90, line width=1pt, distance=3pt]}, pattern color=cyan!70!black}] (F)--(N)--(J)--(C)--cycle;
\path[fill=red!30, postaction={pattern={Lines[angle=85, line width=1pt, distance=3pt]}, pattern color=red!70!black}] (F')--(N')--(J)--(A)--cycle;
\draw (A)--(B)--(C)--cycle ;
\draw (J)--(E) ;
\draw (I)--(M) ;
\draw (F)--(N) ;
\draw (F')--(E') ;
\draw[thick] (M)--(N')--(D)--(M')--cycle ;
\foreach \Coor/\Text/\Pos in
{A/$A$/90,
B/$B$/-135,
C/$C$/-45,
E/$E$/-90,
F/$F$/-90,
I/$I$/180,
J/$J$/0,
M/$M$/-80,
N/$N$/100%
} {%
% \path (\Coor) pic {Cross={2 and black}} ;
%\node[small dot] at (\Coor) {} ;
\node[shift=(\Pos:8pt),anchor=center] at (\Coor) {\Text} ;
}
\end{tikzpicture}
\end{document}
