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

% Ex. No. 125 (Section 17.1.2 : Use of \tkzcname{tkzDefSquare} to obtain an isosceles right-angled triangle)

\begin{tikzpicture}[scale=1]
  \tkzDefPoint(0,0){A}
  \tkzDefPoint(3,0){B}
  \tkzDefSquare(A,B) \tkzGetFirstPoint{C}
  \tkzDrawPolygon[color=blue,fill=blue!30](A,B,C)
\end{tikzpicture}

\end{document}