\input{preamble-standalone.ltx} \begin{document} % Ex. No. 233 (Section 30.2.3 : Archimedes) \begin{tikzpicture}[scale=1.25] \tkzDefPoint(0,0){A}\tkzDefPoint(6,0){D} \tkzDefPoint(8,0){B}\tkzDefPoint(4,0){I} \tkzDefLine[orthogonal=through D](A,D) \tkzInterLC[R](D,tkzPointResult)(I,4 cm) \tkzGetFirstPoint{C} \tkzDefLine[orthogonal=through C](I,C) \tkzGetPoint{c} \tkzDefLine[orthogonal=through B](A,B) \tkzGetPoint{b} \tkzInterLL(C,c)(B,b) \tkzGetPoint{T} \tkzInterLL(A,T)(C,D) \tkzGetPoint{P} \tkzDrawArc(I,B)(A) \tkzDrawSegments(A,B A,T C,D I,C) \tkzDrawSegment[color=orange](I,C) \tkzDrawLine[add = 1 and 0](C,T) \tkzDrawLine[add = 0 and 1](B,T) \tkzMarkRightAngle(I,C,T) \tkzDrawPoints(A,B,I,D,C,T) \tkzLabelPoints(A,B,I,D) \tkzLabelPoints[above right](C,T) \tkzMarkSegment[pos=.25,mark=s|](C,D) \tkzMarkSegment[pos=.75,mark=s|](C,D) \end{tikzpicture} \end{document}