\begin{center}
\begin{tikzpicture}
\tkzDefPoint(0,0){C} \tkzDefPoint(300:1){aH}
\tkzCompass(C,aH) \tkzInterCC(C,aH)(aH,C) \tkzGetPoints{K60X}{K60}
\tkzCompass(C,K60) \tkzCompass(aH,K60)
\tkzInterLC(C,aH)(aH,C) \tkzGetPoints{CAGAIN}{2CM}
\tkzInterLC(C,aH)(2CM,aH) \tkzGetPoints{aHAGAIN}{B}
\tkzCompass(aH,2CM) \tkzCompass(2CM,B)
\tkzDrawLine(C,B) \tkzLabelLine[above left](C,B){$a$}
\tkzInterCC(K60,B)(B,K60) \tkzGetPoints{SEC}{SECX}
\tkzCompass(K60,SEC) \tkzCompass(K60,SECX)
\tkzCompass(B,SEC) \tkzCompass(B,SECX)
\tkzInterLL(SEC,SECX)(C,K60) \tkzGetPoint{A}
\tkzDrawLine(C,A) \tkzLabelLine[above left](C,A){$b$}
\tkzDrawLine(A,B) \tkzLabelLine[above left](A,B){$c$}
\tkzDrawLine(SEC,A)
\tkzDrawPolygon[fill=blue!30, opacity=.30](A,B,C)
\tkzDrawPoints(C) \tkzLabelPoints(C,B,A)
\end{tikzpicture}
\end{center}