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

% Ex. No. 64 (Section 10.1.5 : Option \tkzname{orthogonal} with $K=-1$)

\begin{tikzpicture}[scale=.75]
  \tkzDefPoint(1,2){O}
  \tkzDefPoint(2,5){I}
  \tkzDefPointWith[orthogonal](O,I)
  \tkzGetPoint{J}
  \tkzDefPointWith[orthogonal,K=-1](O,I)
  \tkzGetPoint{K}
  \tkzDrawSegment(O,I)
  \tkzDrawSegments[->](O,J O,K)
  \tkzMarkRightAngles(I,O,J I,O,K)
  \tkzDrawPoints(O,I,J,K)
  \tkzLabelPoints(O,I,J,K)
\end{tikzpicture}

\end{document}