\begin{tikzpicture}[rotate=25]
  \tkzInit
  \tkzDefPoints{-2/0/A,1/2/B}
  \tkzDefLine[mediator](A,B)          \tkzGetPoints{C}{D}
  \tkzDefPointWith[linear,K=.75](C,D) \tkzGetPoint{D}
  \tkzDefMidPoint(A,B)                \tkzGetPoint{I}
  \tkzFillPolygon[color=orange!30](A,C,B,D)
  \tkzDrawSegments(A,B C,D)
  \tkzMarkRightAngle(B,I,C)
  \tkzDrawSegments(D,B D,A)
  \tkzDrawSegments(C,B C,A)
\end{tikzpicture}
