Question

Create a class named MyTriangle that contains the following three methods:

• public static boolean isValid(double sidea, double sideb, double sidec)
• public static double area(double sidea, double sideb, double sidec)
• public static String triangletType(double a, double b, double c)

The isValid method returns true if the sum of the two shorter sides is greater than the longest side. The lengths of the 3 sides of the triangle are sent to this method but you may NOT assume that they are sent in any particular order.

The area method returns the area of the triangle. Given the lengths of the three sides of the triangle, the area of the triangle can be computed using Heron's formula (do the research).

The triangleType method returns one of the following strings: "Equilateral", "Isosceles", "Scalene", "Invalid Triangle". You can determine the triangle's type if a, b, and c represent the sides in ascending order, you must first determine if the triangle is valid. If it is valid, the triangle is equilateral if a == c. Isosceles if a == b or b == c. Scalene otherwise.

Define a main method within your class that inputs from the user three sides for a triangle in any order. The main method should then display the triangle's type. If the triangle is valid, you must also output the area of the triangle. Zip your complete netbeans project and submit it by the due date.

Answer 1

import java.util.Scanner;

public class MyTriangle {

        public static void main(String[] args) {

                Scanner scanner = new Scanner(System.in);

                double sideA, sideB, sideC, areaOfTriangle = 0.0;
                boolean trianlgeValid = false;

                // Asking for sides of triangle as INPUT from user
                sideA = scanner.nextDouble();
                sideB = scanner.nextDouble();
                sideC = scanner.nextDouble();

                // checking if the triangle is VALID or INVALID
                trianlgeValid = isValid(sideA, sideB, sideC);

                if (trianlgeValid == true) {

                        System.out.println("Valid triangle");

                        // If it is valid then calculate the area and type
                        areaOfTriangle = area(sideA, sideB, sideC);

                        System.out.println("Area : " + areaOfTriangle);

                        // Here we are directly printing the returned value from the method
                        System.out.println("Type : " + triangletType(sideA, sideB, sideC));

                } else {
                        // If it is not valid then print this
                        System.out.println("InValid Triangle");
                }

        }

        public static boolean isValid(double sidea, double sideb, double sidec) {

                // Initializing an array for storing the sides of triangle to sort them
                // ascending
                // wise
                double arr[] = new double[3];

                boolean triangleValid = false;

                // Copying the values of sides to array
                arr[0] = sidea;
                arr[1] = sideb;
                arr[2] = sidec;

                // Sorting the sides using SELECTION SORT
                for (int i = 1; i < 3; i++) {
                        double temp = arr[i];
                        int j = i - 1;

                        while (j >= 0 && temp < arr[j]) {
                                arr[j + 1] = arr[j];
                                j = j - 1;
                        }
                        arr[j + 1] = temp;
                }

                // Then again copy the values of array to sides
                sidea = arr[0];
                sideb = arr[1];
                sidec = arr[2];

                // Calculating if the triangle is valid or not
                if ((sidea + sideb) > sidec) {

                        // If it is then
                        triangleValid = true;
                } else {
                        // If it is not then
                        triangleValid = false;
                }

                return triangleValid;
        }

        public static double area(double sidea, double sideb, double sidec) {
                double areaOfTriangle = 0.0, s = 0.0;

                // Here we are calculating the s value according to the HERON'S FORMULA
                s = (sidea + sideb + sidec) / 2.0;

                // And the finding the area using same HERON'S FORMULA
                // We are using (Math.sqrt) to find square root the calculated value
                
                areaOfTriangle = Math.sqrt((s * (s - sidea) * (s - sideb) * (s - sidec)));

                return areaOfTriangle;
        }

        public static String triangletType(double a, double b, double c) {
                String type = "";
                double arr[] = new double[3];

                // Using same technique as used above to sort the sides for calculating their
                // types
                arr[0] = a;
                arr[1] = b;
                arr[2] = c;

                for (int i = 1; i < 3; i++) {
                        double temp = arr[i];
                        int j = i - 1;

                        while (j >= 0 && temp < arr[j]) {
                                arr[j + 1] = arr[j];
                                j = j - 1;
                        }
                        arr[j + 1] = temp;
                }

                a = arr[0];
                b = arr[1];
                c = arr[2];

                // calculating the type
                if (a == c) {
                        type = "Equilateral";

                } else if (a == b || b == c) {
                        type = "Isosceles";
                } else {
                        type = "Scalene";
                }

                // returning the calculated type
                return type;
        }

}