O = Intersect(xAxis, yAxis)
OX = Point(xAxis)
c = Circle(O, OX)
A = Point(c)
B = Point(c)
C = Point(c)
D = Point(c)
AB = Segment(A, B)
BC = Segment(B, C)
CD = Segment(C, D)
DA = Segment(D, A)
AC = Segment(A, C)
DB = Segment(D, B)
BD = Distance(B, D)
vp: (AC * BD)
AD = Distance(A, D)
pp: (AB * CD) + (BC * AD)
text1: "\shadowbox{Ptolemaiose \ teoreem: Kõõlnelinurga \;  diagonaalide \;  korrutis\\on \; võrdne \; vastaskülgede \; korrutiste  \; summaga:\\
\left| AC \right| ·\left| BD \right|=\left| AB \right| ·\left| CD \right|+\left| BC \right| ·\left| AD \right|.
\\
\left| AC \right| ·\left| BD \right|=" + (LaTeX[AC]) + "·" + (LaTeX[BD]) + "=" + (LaTeX[vp]) + "
\\
\left| AB \right| ·\left| CD \right|+\left| BC \right| ·\left| AD \right|=" + (LaTeX[AB]) + "·" + (LaTeX[CD]) + "+" + (LaTeX[BC]) + "·" + (LaTeX[AD]) + "=" + (LaTeX[pp]) + "
}"