Question

Write an interface Shape with methods getShapeName and getPerimeter. Write classes called Square, Rectangle, Circle and Triangle that implement the interface. Supply the proper parameters to the Square, Rectangle, Triangle and Circle constructors such that the perimeter can be calculated. Run THRou JDK compiler please

Sample code:

//Save this in Shape.java
public interface Shape{
        public double getPerimeter();
        public String getShapeName();
}

//Save this in Triangle.java
public class Triangle implements Shape{
        private double side1;
        private double side2;

        Triangle(double length1, double length2, double length3 ){
                side1 = length1;
                side2 = length2;
                side3 = length3;
        }

        public String getShapeName(){
                return "Triangle";
        }
        
        public double getPerimeter(){
                return side1 + side2 + side3;
        }
}


// Save this in Main.java
public class Main{
        public static void main(String[] args){
                Shape shape = new Triangle(3, 4, 5);
                System.out.println(String.valueOf(shape.getPerimeter()));
                System.out.println(shape.getShapeName());

                // Now do the same thing for the Square, Rectangle and Circle classes.

                
                // Shape circle = new Circle(PARAMS);
                // System.out.println(String.valueOf(circle.getPerimeter());
                // System.out.println(circle.getShapeName());

                // Shape square = new Circle(PARAMS);
                // System.out.println(String.valueOf(square.getPerimeter());
                // System.out.println(square.getShapeName());

                // Shape rectangle = new Circle(PARAMS);
                // System.out.println(String.valueOf(rectangle.getPerimeter());
                // System.out.println(rectangle.getShapeName());
        }
}

Answer 1

Below is your code: -

Main.java

public class Main {
   public static void main(String[] args) {
       Shape shape = new Triangle(3, 4, 5);
       System.out.println(String.valueOf(shape.getPerimeter()));
       System.out.println(shape.getShapeName());

       Shape circle = new Circle(3);
       System.out.println(String.valueOf(circle.getPerimeter()));
       System.out.println(circle.getShapeName());

       Shape square = new Square(4);
       System.out.println(String.valueOf(square.getPerimeter()));
       System.out.println(square.getShapeName());

       Shape rectangle = new Rectangle(4, 5);
       System.out.println(String.valueOf(rectangle.getPerimeter()));
       System.out.println(rectangle.getShapeName());
   }
}

Triangle.java

public class Triangle implements Shape{
private double side1;
private double side2;
private double side3;
  
Triangle(double length1, double length2, double length3 ){
side1 = length1;
side2 = length2;
side3 = length3;
}

public String getShapeName(){
return "Triangle";
}
  
public double getPerimeter(){
return side1 + side2 + side3;
}
}

Shape.java

public interface Shape{
public double getPerimeter();
public String getShapeName();
}

Circle.java

public class Circle implements Shape {

   private double radius;

   Circle(double r) {
       this.radius = r;
   }

   public double getPerimeter() {
       return 2 * Math.PI * radius;
   }

   public String getShapeName() {
       return "Circle";
   }

}

Square.java

public class Square implements Shape {

   private double side;

   Square(double s) {
       this.side = s;
   }

   public double getPerimeter() {
       return 4 * side;
   }

   public String getShapeName() {
       return "Square";
   }

}

Rectangle.java

public class Rectangle implements Shape {

   private double length;
   private double breadth;

   Rectangle(double l, double b) {
       this.length = l;
       this.breadth = b;
   }

   public double getPerimeter() {
       return 2 * (this.length + this.breadth);
   }

   public String getShapeName() {
       return "Rectangle";
   }

}

Output

12.0
Triangle
18.84955592153876
Circle
16.0
Square
18.0
Rectangle