update,

_resources/it114105/itp4510/Lab01/Lab1.2/q2/Circle.java

@@ -0,0 +1,12 @@
+public class Circle extends Shape { // line 10
+    private int radius; // line 11
+
+    public Circle(String name, int r) {
+        super(name); // line 12
+        radius = r; // line 13
+    }
+
+    public double area() {
+        return radius * radius * 3.1416;
+    }
+}

_resources/it114105/itp4510/Lab01/Lab1.2/q2/Shape.java

@@ -0,0 +1,9 @@
+public abstract class Shape { // line 1
+    private String name; // line 2
+
+    public Shape(String name) { // line 3
+        this.name = name; // line 4
+    }
+
+    public abstract double area(); // line 5
+}

_resources/it114105/itp4510/Lab01/Lab1.2/q2/Square.java

@@ -0,0 +1,12 @@
+public class Square extends Shape { // line 6
+    private int side; // line 7
+
+    public Square(String name, int side) {
+        super(name); // line 8
+        this.side = side; // line 9
+    }
+
+    public double area() {
+        return side * side;
+    }
+}

_resources/it114105/itp4510/Lab01/Lab1.2/q2/TestShape.java

@@ -0,0 +1,8 @@
+public class TestShape {
+    public static void main(String[] args) { // line 14
+        Shape s1 = new Square("Square1", 4); // line 15
+        Shape s2 = new Circle("Circle1", 2); // line 16
+        System.out.println("Area of circle: " + s2.area()); // line 17
+        System.out.println("Area of square: " + s1.area()); // line 18
+    }
+}