\input{preamble-standalone.ltx}
\begin{document}

% Ex. No. 190 (Section 22.6.1 : Folding)

\begin{tikzpicture}
  \tkzDefPoint(1,5){A}
  \tkzDefPoint(5,2){B}
  \tkzDrawSegment(A,B)
  \tkzFindSlopeAngle(A,B)
  \tkzGetAngle{tkzang}
  \tkzDefPointBy[rotation= center A angle \tkzang ](B)
  \tkzGetPoint{C}
  \tkzDefPointBy[rotation= center A angle -\tkzang ](B)
  \tkzGetPoint{D}
  \tkzCompass[orange,length=1](A,C)
  \tkzCompass[orange,delta=10](B,C)
  \tkzDrawPoints(A,B,C,D)
  \tkzLabelPoints(B,C,D)
  \tkzLabelPoints[above left](A)
  \tkzDrawSegments[style=dashed,color=orange](A,C A,D)
\end{tikzpicture}

\end{document}