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

% Ex. No. 229 (Section 30.1.4 : Triangle altitudes)

\begin{tikzpicture}[scale=.8]
   \tkzDefPoint(0,0){C}
   \tkzDefPoint(7,0){B}
   \tkzDefPoint(5,6){A}
   \tkzDrawPolygon(A,B,C)
   \tkzDefMidPoint(C,B)
   \tkzGetPoint{I}
   \tkzDrawArc(I,B)(C)
   \tkzInterLC(A,C)(I,B)
   \tkzGetSecondPoint{B'}
   \tkzInterLC(A,B)(I,B)
   \tkzGetFirstPoint{C'}
   \tkzInterLL(B,B')(C,C')
   \tkzGetPoint{H}
   \tkzInterLL(A,H)(C,B)
   \tkzGetPoint{A'}
     \tkzDefCircle[circum](A,B',C')
    \tkzGetPoint{O}
   \tkzDrawCircle[color=red](O,A)
   \tkzDrawSegments[color=orange](B,B' C,C' A,A')
   \tkzMarkRightAngles(C,B',B B,C',C C,A',A)
   \tkzDrawPoints(A,B,C,A',B',C',H)
   \tkzLabelPoints(A,B,C,A',B',C',H)
\end{tikzpicture}

\end{document}