\documentclass[tikz]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.15}
\usepackage{mathrsfs}
\usetikzlibrary{arrows,calc}
\usepackage{tkz-euclide}
\pagestyle{empty}

\definecolor{AngleClr}{rgb}{0,0.39215686274509803,0}
\definecolor{ShapeClr}{rgb}{0.6,0.2,0}
\definecolor{BlueSqr}{RGB}{5,81,163}

\begin{document}

\begin{tikzpicture}[scale=.75]
\tkzSetUpLine[line width=1pt,color=black]
\tkzSetUpPoint[fill=black]

\tkzDefPoint(50:2.5){B}
\tkzDefPoint(125:2.5){A}
\tkzDefPoint(235:2.5){D}
\tkzDefPoint(0:2.5){C}


\tkzDefTriangleCenter[circum](A,B,C) \tkzGetPoint{O}

\tkzFillPolygon[fill=ShapeClr,fill opacity=0.1](A,B,C,D)

\tkzDrawSegments[line width=0.5pt,color=black](A,C B,D)

\tkzDrawPolygon[color=ShapeClr](A,B,C,D)
\tkzDrawCircle[line width=0.75pt,color=black](O,A)

\tkzDrawPoints[size=3](A,B,C,D)

\tkzLabelPoint[above left](A){$\mathrm{A}$}
\tkzLabelPoint[above right](B){$\mathrm{B}$}
\tkzLabelPoint[right](C){$\mathrm{\Gamma}$}
\tkzLabelPoint[below](D){$\rm \Delta$}

\tkzLabelSegments[above=-0.05cm,sloped](A,B){\scalebox{0.75}{$\rm AB$} }
\tkzLabelSegments[below=-0.05cm,sloped](B,C){\scalebox{0.75}{$\rm B\Gamma$} }
\tkzLabelSegments[below,sloped](C,D){\scalebox{0.75}{$\rm \Gamma\Delta$} }
\tkzLabelSegments[above,sloped](D,A){\scalebox{0.75}{$\rm \Delta A$} }

\tkzLabelSegments[above,sloped,pos=0.4](A,C){\scalebox{0.75}{$\rm A\Gamma$} }
\tkzLabelSegments[above,sloped](B,D){\scalebox{0.75}{$\rm B\Delta$} }

\end{tikzpicture}
\end{document}