\ANG{
Der W"urfel $ABCDEFG$ wird durch die Ebene $E(XYZ)$ in zwei Teile
zerschnitten. Konstruiere die Schnittfigur im Schr"agbild.

$$
\beginpicture
\setcoordinatesystem units <1mm,1mm>
\setplotarea x from -10 to 115, y from -25 to 95
\setdots <1mm>
  \grid 25 24
\plotsymbolspacing 0.25 pt

% Wuerfel ------------------------------------------
\setsolid
\plot   30  0      90   0      90  60    30  60   30  0  /
\plot   30  0       0  30       0  90    60  90   90 60  /
\plot   30 60       0  90      /
\setdashes
\plot    0 30      60  30      60  90    /
\plot   60 30      90   0       /                                          
\put {A} at 27  -3 
\put {B} at 93  -3
\put {C} at 63  33
\put {D} at -3  33
\put {E} at 27  57 
\put {F} at 93  57
\put {G} at 63  93
\put {H} at -3  93
%Ebenenstueck
\multiput {\circle*{2.5}}[Bl] at           
            40  90      80  70     90   40  /  
\setsolid
\plot 40  90    80  70     90   40 /
\put {$X$} at  38  93
\put {$Y$} at  87  70
\put {$Z$} at  93  40
% ------------------------------------------------
\endpicture
$$
}
\LSG{\mbox{}
}
