2 files changed, 84 insertions, 1 deletions
diff --git a/java/alist.txt b/java/alist.txt
index 6e11a63..2dcc72d 100644
--- a/java/alist.txt
+++ b/java/alist.txt
@@ -10,4 +10,5 @@ StaticExecution
 SingletonExample 
 StudentsArray
 BankAccountExample
-
+ShapeAreaCalculations
+AbstractShapeCalculations
diff --git a/java/code/AbstractShapeCalculations.java b/java/code/AbstractShapeCalculations.java
new file mode 100644
index 0000000..3f18c0c
--- /dev/null
+++ b/java/code/AbstractShapeCalculations.java
@@ -0,0 +1,82 @@
+import java.util.Scanner;
+import java.util.InputMismatchException;
+
+abstract class Shape {
+	abstract double area();
+	abstract void display();
+}
+
+class Rectangle extends Shape {
+	double length, width;
+	Rectangle(double len, double wid) {
+		length = len;
+		width = wid;
+	}
+	double area() {
+		return length * width;
+	}
+	void display() {
+		System.out.println("A rectangle with length " + length + " units and width " + width + " units has the area of " + area() + " square units.");
+	}
+}
+
+class Circle extends Shape {
+	double radius;
+	Circle(double r) {
+		radius = r;
+	}
+	double area() {
+		return Math.PI * radius * radius;
+	}
+	void display() {
+		System.out.println("A circle with radius " + radius + " units has the area of " + area() + " square units.");
+	}
+}
+
+class Triangle extends Shape {
+	double a, b, c;
+	Triangle(double s1, double s2, double s3) {
+		a = s1;
+		b = s2;
+		c = s3;
+	}
+	double perimeter() {
+		return a + b + c;
+	}
+	double area() {
+		var s = perimeter() / 2.0;
+		return Math.sqrt(s * (s - a) * (s - b) * (s - c));
+	}
+	void display() {
+		System.out.println("A triangle with side lengths " + a + " units, " + b + "units and " + c + " units has the area of " + area() + " square units.");
+	}
+}
+
+class AbstractShapeCalculations {
+    public static void main(String[] args) {
+        try {
+            Scanner sc = new Scanner(System.in);
+            System.out.println("Calculate and display shapes\n");
+            System.out.println("Rectangle");
+            System.out.print("  Enter length: ");
+            double length = sc.nextDouble();
+            System.out.print("  Enter width: ");
+            double width = sc.nextDouble();
+            Shape s;
+            s = new Rectangle(length, width);
+            s.display();
+            System.out.println("Circle");
+            System.out.print("  Enter radius: ");
+            double radius = sc.nextDouble();
+            s = new Circle(radius);
+            s.display();
+            System.out.println("Triangle");
+            System.out.print("  Enter three side lengths: ");
+            double a = sc.nextDouble(), b = sc.nextDouble(), c = sc.nextDouble();
+            s = new Triangle(a, b, c);
+            s.display();
+        } catch (InputMismatchException e) {
+            System.err.println("Invalid numbers in input");
+        }
+    }
+}