Question

Welcome to the Triangles program

Enter length 1: 3

Enter length 2: 5

Enter length 3: 5

Enter the base: 5

Enter the height: 8

---------------------

The triangle is Isosceles since it has two equal length sides.
Isosceles triangle also has two equal angles

The area is: 20

The permimeter is: 13

Continue? (y/n): y

Enter length 1: 10

Enter length 2: 10

Enter length 3: 10

Enter the base: 10

Enter the height: 7

---------------------

The triangle is Equilateral since it has equal length on all three sides.
All Equilateral triangle are equiangular triangles.

The area is: 35

The permimeter is: 30

Continue? (y/n): y

Enter length 1: 10

Enter length 2: 3

Enter length 3: 9

Enter the base: 10

Enter the height: 7

---------------------

The triangle is Scalene with all no equal side.
Scalene triangles have no equal angles.

The area is: 35

The permimeter is: 22

Continue? (y/n): n

Goodbye.

------------------------------------------------

Requirements:

• Use a main class for accepting inputs and validating inputs
  • Create an object of type class triangle
  • Prompt the user to enter the three sides of a triangle.
  • Prompt the user for the base and the height
  • Accept decimal values
  • Validate input using try-catch and also nested-if statements as needed
  • If the user enters invalid data, the application displays an appropriate error message and prompts the user again until the user enters valid data.
    • Use a method for evaluating what type of triangle it is (call the method via the object, NO STATIC METHOD)
    • Use a method for calculating the area = (base * height)/2 (call the method via the object, NO STATIC METHOD)
    • Use a method for calculating the perimeter = (length1 + length2 + length3) (call the method via the object, NO STATIC METHOD)
      
• After displaying all the triangle information, the application prompts the user to continue.
• When the user chooses not to continue, the application displays a goodbye message

DBPM Template

**DBPM TEMPLATE **

package triangles;
import java.util.Scanner;
public class Triangles
{
private double area;
private double permimeter;

//CREATE A DEFAULT CONSTRUCTOR TO INITIALIZE area and permimeter

//CREATE THE TWO SETTER METHODS FOR area and permimeter

//CREATE THE TWO GETTER METHODS FOR area and permimeter

public void triangleType(double side1, double side2, double side3)
{
if (side1 == side2 && side1 == side3) {
System.out.println("The triangle is Equilateral since it has equal length on all three sides.");
System.out.println("All Equilateral triangle are equiangular triangles.");

} else {
if (side1 == side2 && side1 != side3 || side1 != side2 && side2 == side3 || side1 == side3 && side1 != side2) {
System.out.println("The triangle is Isosceles since it has two equal length sides.");
System.out.println("Isosceles triangle also has two equal angles");

} else {
if (side1 != side2 && side1 != side3) {
System.out.println("The triangle is Scalene with all no equal side.");
System.out.println("Scalene triangles have no equal angles.");

}
}
}
}
//WRITE THE AREA METHOD WITH TWO DOUBLE PARAMETERS WITH A VOID RETURN TYPE
{
// CALCULATE THE AREA (this.area)
System.out.println(this.area);
}

//WRITE THE PERMIMETER METHOD WITH THREE DOUBLE PARAMETERS WITH A VOID RETURN TYPE
{
// CALCULATE THE PERMIMETER (this.permimeter)
System.out.println(this.permimeter);
}

public static void main(String[] args)
{
System.out.println("Welcome to the triangles program");
Scanner key = new Scanner(System.in);
int x = 1;
String y = "y";

//CREATE A TRIANGLES OBJECT CALLED triangleObj

do {
try {
while ("y".equalsIgnoreCase(y)) {
x = 1;
System.out.print("Enter length 1: ");
double side1 = key.nextDouble();

System.out.print("Enter length 2: ");
double side2 = key.nextDouble();

System.out.print("Enter length 3: ");
double side3 = key.nextDouble();

System.out.println(" ");

System.out.print("Enter the Base: ");
double base = key.nextDouble();

System.out.print("Enter the Height: ");
double height = key.nextDouble();

System.out.println(" ");
System.out.println("---------------------");
System.out.println(" ");
triangleObj.triangleType(side1, side2, side3);
triangleObj.area(base, height);
triangleObj.permimeter(side1, side2, side3);
x = 2;

System.out.print("Continue? Y/N: ");
y = key.nextLine();
y = key.nextLine();
}
}
//CREATE THE CATCH CLAUSE WITH Exception e
{
System.out.println("Please enter a valid number.");
key.next();
}
} while (x == 1);
}
}

Answer 1

Note: Done accordingly. Please comment for any further help. Please give thumbs up.

Code:

import java.util.Scanner;

public class Triangles {
private double area;
private double perimeter;

// CREATE A DEFAULT CONSTRUCTOR TO INITIALIZE area and permimeter
Triangles() {
this.area = 0;
this.perimeter = 0;
}
// CREATE THE TWO SETTER METHODS FOR area and permimeter
void setArea(double area) {
this.area = area;
}

void setPerimeter(double perimeter) {
this.perimeter = perimeter;
}
// CREATE THE TWO GETTER METHODS FOR area and permimeter
double getPerimeter() {
return this.perimeter;
}

double getArea() {
return this.area;
}

public void triangleType(double side1, double side2, double side3) {
if (side1 == side2 && side1 == side3) {
System.out.println("The triangle is Equilateral since it has equal length on all three sides.");
System.out.println("All Equilateral triangle are equiangular triangles.");

} else {
if (side1 == side2 && side1 != side3 || side1 != side2 && side2 == side3 ||
side1 == side3 && side1 != side2) {
System.out.println("The triangle is Isosceles since it has two equal length sides.");
System.out.println("Isosceles triangle also has two equal angles");

} else {
if (side1 != side2 && side1 != side3) {
System.out.println("The triangle is Scalene with all no equal side.");
System.out.println("Scalene triangles have no equal angles.");
}
}
}
}

// WRITE THE AREA METHOD WITH TWO DOUBLE PARAMETERS WITH A VOID RETURN TYPE
void area(double base, double height) {
this.area = (1 / 2.0) * base * height;
}

// WRITE THE PERMIMETER METHOD WITH THREE DOUBLE PARAMETERS WITH A VOID
// RETURN TYPE
void perimeter(double side1, double side2, double side3) {
this.perimeter = side1 + side2 + side3;
}

public static void main(String[] args) {
System.out.println("Welcome to the triangles program");
Scanner key = new Scanner(System.in);
int x = 1;
String y = "y";

//CREATE A TRIANGLES OBJECT CALLED triangleObj
while ("Y".equalsIgnoreCase(y)) {
Triangles triangleObj = new Triangles();
try {
System.out.print("Enter length 1: ");
double side1 = key.nextDouble();

System.out.print("Enter length 2: ");
double side2 = key.nextDouble();

System.out.print("Enter length 3: ");
double side3 = key.nextDouble();

System.out.println(" ");

System.out.print("Enter the Base: ");
double base = key.nextDouble();

System.out.print("Enter the Height: ");
double height = key.nextDouble();

System.out.println(" ");
System.out.println("---------------------");
System.out.println(" ");
triangleObj.triangleType(side1, side2, side3);
triangleObj.area(base, height);
triangleObj.perimeter(side1, side2, side3);
System.out.println("The area is: "+triangleObj.area);
System.out.println("The perimeter is: "+triangleObj.perimeter);
  
System.out.print("Continue? Y/N: ");
key.nextLine();//to clear buffer
y = key.nextLine();
}
//CREATE THE CATCH CLAUSE WITH Exception e
catch (Exception e) {
System.out.println("Please enter a valid number.");
key.nextLine();//to clear buffer
System.out.print("Continue? Y/N: ");
y = key.nextLine();
}
}
System.out.println("Goodbye.");
}
}

Output: