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feature feature
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- FIGURE
* OPEN_ FIGURE * CLOSED_ FIGURE * SEGMENT POLYLINE POLYGON ELLIPSE CIRCLE RECTANGLE TRIANGLE SQUARE
center* display* rotate* perimeter* perimeter
+
perimeter+ perimeter++ diagonal
... ...
perimeter++
+ +
side2 * deferred + effective ++ redefined perimeter++ side1
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6& ='&
- vertex [i ]
vertex [i + 1]
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