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

% Ex. No. 28 (Section  4.2.2 : Equilateral triangle)

\begin{tikzpicture}[scale=1]
 \tkzDefPoint(2,3){A}
 \tkzDefShiftPoint[A](30:3){B}
 \tkzDefShiftPoint[A](-30:3){C}
 \tkzDrawPolygon(A,B,C)
 \tkzDrawPoints(A,B,C)
 \tkzLabelPoints(B,C)
 \tkzLabelPoints[above left](A)
 \tkzMarkSegments[mark=|,color=red](A,B A,C B,C)
\end{tikzpicture}

\end{document}