Java: Abstract GeometricShape Class with Triangle and Square Subclasses

// GeometricShape.java
// Define an abstract class named GeometricShape
abstract class GeometricShape {
  // Declare an abstract method named area that returns a double
  public abstract double area();

  // Declare an abstract method named perimeter that returns a double
  public abstract double perimeter();
} 

// Triangle.java
// Define a class named Triangle that extends GeometricShape
class Triangle extends GeometricShape {
  // Declare private instance variables for the sides of the triangle
  private double side1;
  private double side2;
  private double side3;

  // Define a constructor that initializes the sides of the triangle
  public Triangle(double side1, double side2, double side3) {
    // Assign the parameters to the instance variables
    this.side1 = side1;
    this.side2 = side2;
    this.side3 = side3;
  }

  // Override the area method from GeometricShape
  @Override
  // Implementation of the area method that calculates and returns the area of the triangle
  public double area() {
    // Calculate the semi-perimeter of the triangle
    double s = (side1 + side2 + side3) / 2;
    // Calculate and return the area using Heron's formula
    return Math.sqrt(s * (s - side1) * (s - side2) * (s - side3));
  }

  // Override the perimeter method from GeometricShape
  @Override
  // Implementation of the perimeter method that returns the perimeter of the triangle
  public double perimeter() {
    // Return the sum of the sides of the triangle
    return side1 + side2 + side3;
  }
} 

// Square.java
// Define a class named Square that extends GeometricShape
class Square extends GeometricShape {
  // Declare a private instance variable for the side of the square
  private double side;

  // Define a constructor that initializes the side of the square
  public Square(double side) {
    // Assign the parameter to the instance variable
    this.side = side;
  }

  // Override the area method from GeometricShape
  @Override
  // Implementation of the area method that calculates and returns the area of the square
  public double area() {
    // Calculate and return the area by squaring the side length
    return side * side;
  }

  // Override the perimeter method from GeometricShape
  @Override
  // Implementation of the perimeter method that returns the perimeter of the square
  public double perimeter() {
    // Calculate and return the perimeter by multiplying the side length by 4
    return 4 * side;
  }
} 

// Define the Main class
public class Main {
  // Main method: entry point of the program
  public static void main(String[] args) {
    // Create a Triangle object with sides 4, 5, and 6
    GeometricShape triangle = new Triangle(4, 5, 6);
    // Create a Square object with side length 6
    GeometricShape square = new Square(6);

    // Print the area of the triangle
    System.out.println("Triangle Area: " + triangle.area());
    // Print the perimeter of the triangle
    System.out.println("Triangle Perimeter: " + triangle.perimeter());

    // Print the area of the square
    System.out.println("Square Area: " + square.area());
    // Print the perimeter of the square
    System.out.println("Square Perimeter: " + square.perimeter());
  }
}