Question

The Triangle Inequality Theorem states that the sum of any two sides is greater than the other side.

Write in Java a Triangle class that has

• a constructor that takes the values of three sides as it's parameters, checks if the triangular inequality theorem is satisfied and assigns the values to the class variables. If the triangular inequality is not satisfied, the constructor throws an exception.

• a toString() method that returns the three sides of the triangle.

The main method should create a triangle object and handle the exception by displaying an appropriate message.

Answer 1

public class Triangle {

    private double side1;
    private double side2;
    private double side3;

    public Triangle(double side1, double side2, double side3) {
        if (side1 >= side2 + side3 || side2 >= side1 + side3 || side3 >= side1 + side2)
            throw new IllegalArgumentException(side1 + ", " + side2 + " and " + side3 + " do not form sides of a triangle.");
        this.side1 = side1;
        this.side2 = side2;
        this.side3 = side3;
    }

    @Override
    public String toString() {
        return "Sides of triangle are " + side1 + ", " + side2 + " and " + side3;
    }

    public static void main(String[] args) {
        Triangle triangle = new Triangle(3, 4, 5);
        System.out.println(triangle);

        try {
            Triangle badTriangle = new Triangle(3, 8, 4);
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
}