How to combine three animations as the following example?
\documentclass[pstricks,border=12pt,12pt]{standalone}
\usepackage{pstricks-add,pst-eucl}%
\def\first#1{%
\pnodes(3,3){A}(1,-1){B}(7,-1){C}
\psset{PointSymbol=none,PointName=none}
\pstMiddleAB[PosAngle=135]{A}{B}{M}
\pstMiddleAB{A}{C}{N}
\pstMiddleAB{M}{N}{I}
\pstSegmentMark[SegmentSymbol=pstslash]{A}{M}
\pstSegmentMark[SegmentSymbol=MarkHash]{A}{N}
\pstSegmentMark[SegmentSymbol=MarkHashh]{M}{N}
\pstMarkAngle[fillstyle=solid,fillcolor=green]{N}{M}{A}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{A}{N}{M}{}
\pspolygon(A)(M)(N)
\pstRotation[RotAngle=#1]{I}{A,M,N}[a,m,n]%%%%<<--
\pstMarkAngle[fillstyle=solid,fillcolor=green]{n}{m}{a}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a}{n}{m}{}
\pspolygon[linecolor=red](a)(m)(n)}
\def\second#1{%
\pnodes(3,3){A}(1,-1){B}(7,-1){C}
\psset{PointSymbol=none,PointName=none}
\pstMiddleAB[PosAngle=135]{A}{B}{M}
\pstMiddleAB{A}{C}{N}
\pstMiddleAB{M}{N}{I}
\pstRotation[RotAngle=-180]{I}{A,M,N}[a,m,n]%%%%<<--
\pstMarkAngle[fillstyle=solid,fillcolor=green]{n}{m}{a}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a}{n}{m}{}
\pspolygon[linecolor=red](a)(m)(n)
\pstMiddleAB{a}{n}{I1}
\pstRotation[RotAngle=#1]{I1}{a,m,n}[a1,m1,n1]%%%%<<--
\pstSegmentMark[SegmentSymbol=pstslash]{a1}{m1}
\pstSegmentMark[SegmentSymbol=MarkHashhh]{n1}{m1}
\pstMarkAngle[fillstyle=solid,fillcolor=green]{n1}{m1}{a1}{}
%\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a}{n}{m}{}
\pspolygon[linecolor=red](a1)(m1)(n1)}
\def\third#1{
\pnodes(3,3){A}(1,-1){B}(7,-1){C}
\psset{PointSymbol=none,PointName=none}
\pstMiddleAB[PosAngle=135]{A}{B}{M}
\pstMiddleAB{A}{C}{N}
\pstMiddleAB{M}{N}{I}
\pstRotation[RotAngle=-180]{I}{A,M,N}[a,m,n]%%%%<<--
\pstMarkAngle[fillstyle=solid,fillcolor=green]{n}{m}{a}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a}{n}{m}{}
\pspolygon[linecolor=red](a)(m)(n)
\pstMiddleAB{a}{m}{I2}
\pstRotation[RotAngle=#1]{I2}{a,m,n}[a2,m2,n2]%%%%<<--
\pstSegmentMark[SegmentSymbol=MarkHashh]{a2}{m2}
\pstSegmentMark[SegmentSymbol=MarkHashhh]{n2}{m2}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a2}{n2}{m2}{}
\pspolygon[linecolor=red](a2)(m2)(n2)}
\begin{document}
\foreach \i in {0,-10,...,-180}{%
\begin{pspicture}[showgrid](0,-3)(8,4)
\first{\i}
\end{pspicture}}
\foreach \i in {0,-10,...,-180}{%
\begin{pspicture}[showgrid](0,-3)(8,4)
\first{0}
\second{\i}
\end{pspicture}}
\foreach \i in {0,-10,...,-180}{%
\begin{pspicture}[showgrid](0,-3)(8,4)
\first{0}
\second{-180}
\third{\i}
\end{pspicture}}
\end{document}
ex2 also needs the last image (180°) from ex1 and ex3 also needs the last images from ex1 and ex2:
\documentclass[pstricks,border=15pt]{standalone}
\usepackage{pstricks-add,pst-eucl}%
\begin{document}
\multido{\i=0+3}{60}{%
\begin{pspicture}[showgrid](0,-3)(8,4)
\pnodes(3,3){A}(1,-1){B}(7,-1){C}
\psset{PointSymbol=none,PointName=none}
\pstMiddleAB[PosAngle=135]{A}{B}{M}
\pstMiddleAB{A}{C}{N}
\pstMiddleAB{M}{N}{I}
\pstSegmentMark[SegmentSymbol=pstslash]{A}{M}
\pstSegmentMark[SegmentSymbol=MarkHash]{A}{N}
\pstSegmentMark[SegmentSymbol=MarkHashh]{M}{N}
\pstMarkAngle[fillstyle=solid,fillcolor=green]{N}{M}{A}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{A}{N}{M}{}
\pspolygon(A)(M)(N)
\pstRotation[RotAngle=\i]{I}{A,M,N}[a,m,n]%%%%<<--
\pstMarkAngle[fillstyle=solid,fillcolor=green]{n}{m}{a}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a}{n}{m}{}
\pspolygon[linecolor=red](a)(m)(n)
\end{pspicture}%
}
\multido{\i=0+3}{60}{%
\begin{pspicture}[showgrid](0,-3)(8,4)
\pnodes(3,3){A}(1,-1){B}(7,-1){C}
\psset{PointSymbol=none,PointName=none}
\pstMiddleAB[PosAngle=135]{A}{B}{M}
\pstMiddleAB{A}{C}{N}
\pstMiddleAB{M}{N}{I}
\pstSegmentMark[SegmentSymbol=pstslash]{A}{M}
\pstSegmentMark[SegmentSymbol=MarkHash]{A}{N}
\pstSegmentMark[SegmentSymbol=MarkHashh]{M}{N}
\pstMarkAngle[fillstyle=solid,fillcolor=green]{N}{M}{A}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{A}{N}{M}{}
\pspolygon(A)(M)(N)
\pstRotation[RotAngle=180]{I}{A,M,N}[a,m,n]%%%%<<--
\pstMarkAngle[fillstyle=solid,fillcolor=green]{n}{m}{a}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a}{n}{m}{}
\pspolygon[linecolor=red](a)(m)(n)
% ------------------ end ex1 --------------------------
\pstRotation[RotAngle=-180]{I}{A,M,N}[a,m,n]%%%%<<--
\pstMarkAngle[fillstyle=solid,fillcolor=green]{n}{m}{a}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a}{n}{m}{}
\pspolygon[linecolor=red](a)(m)(n)
\pstMiddleAB{a}{n}{I1}
\pstRotation[RotAngle=\i]{I1}{a,m,n}[a1,m1,n1]%%%%<<--
\pstSegmentMark[SegmentSymbol=pstslash]{a1}{m1}
\pstSegmentMark[SegmentSymbol=MarkHashhh]{n1}{m1}
\pstMarkAngle[fillstyle=solid,fillcolor=green]{n1}{m1}{a1}{}
%\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a}{n}{m}{}
\pspolygon[linecolor=red](a1)(m1)(n1)
\end{pspicture}%
}
\multido{\i=0+3}{61}{%
\begin{pspicture}[showgrid](0,-3)(8,4)
\pnodes(3,3){A}(1,-1){B}(7,-1){C}
\psset{PointSymbol=none,PointName=none}
\pstMiddleAB[PosAngle=135]{A}{B}{M}
\pstMiddleAB{A}{C}{N}
\pstMiddleAB{M}{N}{I}
\pstSegmentMark[SegmentSymbol=pstslash]{A}{M}
\pstSegmentMark[SegmentSymbol=MarkHash]{A}{N}
\pstSegmentMark[SegmentSymbol=MarkHashh]{M}{N}
\pstMarkAngle[fillstyle=solid,fillcolor=green]{N}{M}{A}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{A}{N}{M}{}
\pspolygon(A)(M)(N)
\pstRotation[RotAngle=180]{I}{A,M,N}[a,m,n]%%%%<<--
\pstMarkAngle[fillstyle=solid,fillcolor=green]{n}{m}{a}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a}{n}{m}{}
\pspolygon[linecolor=red](a)(m)(n)
% ------------------ end ex1 --------------------------
\pstRotation[RotAngle=-180]{I}{A,M,N}[a,m,n]%%%%<<--
\pstMarkAngle[fillstyle=solid,fillcolor=green]{n}{m}{a}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a}{n}{m}{}
\pspolygon[linecolor=red](a)(m)(n)
\pstMiddleAB{a}{n}{I1}
\pstRotation[RotAngle=180]{I1}{a,m,n}[a1,m1,n1]%%%%<<--
\pstSegmentMark[SegmentSymbol=pstslash]{a1}{m1}
\pstSegmentMark[SegmentSymbol=MarkHashhh]{n1}{m1}
\pstMarkAngle[fillstyle=solid,fillcolor=green]{n1}{m1}{a1}{}
%\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a}{n}{m}{}
\pspolygon[linecolor=red](a1)(m1)(n1)
% ------------------ end ex2 --------------------------
\pstRotation[RotAngle=-180]{I}{A,M,N}[a,m,n]%%%%<<--
\pstMarkAngle[fillstyle=solid,fillcolor=green]{n}{m}{a}{}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a}{n}{m}{}
\pspolygon[linecolor=red](a)(m)(n)
\pstMiddleAB{a}{m}{I2}
\pstRotation[RotAngle=\i]{I2}{a,m,n}[a2,m2,n2]%%%%<<--
\pstSegmentMark[SegmentSymbol=MarkHashh]{a2}{m2}
\pstSegmentMark[SegmentSymbol=MarkHashhh]{n2}{m2}
\pstMarkAngle[fillstyle=solid,fillcolor=blue]{a2}{n2}{m2}{}
\pspolygon[linecolor=red](a2)(m2)(n2)
\end{pspicture}%
}
\end{document}
There are a lot of duplicate commands which can be deleted. I leave it to you!