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diff --git a/docs/dist/examples/tracing/TwoDShape.java b/docs/dist/examples/tracing/TwoDShape.java
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+/*
+
+Copyright (c) Xerox Corporation 1998-2002.  All rights reserved.
+
+Use and copying of this software and preparation of derivative works based
+upon this software are permitted.  Any distribution of this software or
+derivative works must comply with all applicable United States export control
+laws.
+
+This software is made available AS IS, and Xerox Corporation makes no warranty
+about the software, its performance or its conformity to any specification.
+
+|<---            this code is formatted to fit into 80 columns             --->|
+|<---            this code is formatted to fit into 80 columns             --->|
+|<---            this code is formatted to fit into 80 columns             --->|
+
+*/
+
+
+package tracing;
+
+/**
+ *
+ * TwoDShape is an abstract class that defines generic functionality 
+ * for 2D shapes.
+ *
+ */
+public abstract class TwoDShape {
+    /**
+     * Coordinates of the center of the shape.
+     */
+    protected double x, y;
+
+    protected TwoDShape(double x, double y) {
+        this.x = x; this.y = y;
+    }
+
+    /**
+     * Returns the x coordinate of the shape.
+     */
+    public double getX() { return x; }
+
+    /**
+     * Returns the y coordinate of the shape.
+     */
+    public double getY() { return y; }
+
+    /**
+     * Returns the distance between this shape and the shape given as
+     * parameter.
+     */
+    public double distance(TwoDShape s) {
+        double dx = Math.abs(s.getX() - x);
+        double dy = Math.abs(s.getY() - y);
+        return Math.sqrt(dx*dx + dy*dy);
+    }
+
+    /**
+     * Returns the perimeter of this shape. Must be defined in
+     * subclasses.
+     */
+    public abstract double perimeter();
+
+    /**
+     * Returns the area of this shape. Must be defined in
+     * subclasses.
+     */
+    public abstract double area();
+
+    /**
+     * Returns a string representation of 2D shapes -- simply its
+     * coordinates.
+     */
+    public String toString() {
+        return (" @ (" + String.valueOf(x) + ", " + String.valueOf(y) + ") ");
+    }
+}
+