update,

it114105/itp4510/Lab01/Lab1.2/q3/Circle.java

@@ -0,0 +1,34 @@
+public class Circle extends Shape{
+    private double radius;
+    private Point center;
+
+    public Circle(double radius, double x, double y){
+        super("circle");
+        this.radius = radius;
+        center = new Point(x, y);
+    }
+
+    public double getRadius(){
+        return radius;
+    }
+
+    public Point getCenter(){
+        return center;
+    }
+
+    public void setRadius(double radius){
+        this.radius = radius;
+    }
+
+    public void setCenter(Point center){
+        this.center = center;
+    }
+
+    public double getArea(){
+        return radius*radius*3.1416;
+    }
+
+    public String toString(){
+        return "center=" + center.toString() + "; radius=" + radius;
+    }
+}