How to use Conditional statements with strings? [duplicate]

I am a class 9 student, and I wanted to know how to include strings in if statements Please help

Any sort of help would be lovely just tell me what to do

Thanks in advance!

The code is a bit long but it is just the statements I am using BlueJ

if you can Please do explain your answers

I do believe the problem is in the shape== line

import java.util.*;
public class AreaOf2D
{
    public static void main(String[]args)
    {
        Scanner input = new Scanner(System.in);
        //to calculate area of 2d figures
        System.out.println("Area Calculator");
        System.out.println(" ");
        System.out.print("Enter the Shape: ");
        String Shape = input.nextLine();
        System.out.println(" ");



        //Condition Statements
        if(Shape=="triangle")
        {

            //base
            System.out.print("Enter the Base: ");
            double BaseTri = input.nextDouble();
            System.out.println(" ");

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

            //The formulaes
            double tri = ((1/2) * BaseTri * HeightTri);


            //answer
            System.out.print("The Area of the triangle is: " + tri);
        }
        if(Shape=="square")
        {
            //Side
            System.out.print("Enter the Side: ");
            double Side = input.nextDouble();
            System.out.println(" ");

            //formulae
            double sqr = (Math.pow(Side,2));

            //answer
            System.out.print("The Area of the Square is: " + sqr);
        }
        if(Shape=="rectangle")
        {
            //Length
            System.out.print("Enter the Length: ");
            double Length = input.nextDouble();
            System.out.println(" ");

            //Height
            System.out.print("Enter the Height: ");
            double Height = input.nextDouble();

            //formulaes
            double rec = ((Length * Height));

            //answer
            System.out.print("The Area of the Rectangle is: " + rec);
        }
        if(Shape=="rhombus")
        {
            //Diagonal1
            System.out.print("Enter the first Diagonal: ");
            double Diagonal1 = input.nextDouble();
            System.out.println(" ");

            //Diagonal2
            System.out.print("Enter the second Diagonal: ");
            double Diagonal2 = input.nextDouble();

            //formulae
            double rho = ((1/2) * Diagonal1 * Diagonal2);

            //answer
            System.out.print("The Area of the Rhombus is: " + rho);
        }
        if(Shape=="parallelogram")
        {
            //BasePar
            System.out.print("Enter the Base: ");
            double BasePar = input.nextDouble();
            System.out.println(" ");

            //Diagonal2
            System.out.print("Enter the second Diagonal: ");
            double HeightPar = input.nextDouble();

            //formulae
            double par = ( BasePar * HeightPar);

            //answer
            System.out.print("The Area of the Parallelogram is: " + par);
        }
        if(Shape=="kite")
        {
            //Diagonal1kit
            System.out.print("Enter the first diagonal: ");
            double Diagonal1kit = input.nextDouble();
            System.out.println(" ");

            //Diagonal2kit
            System.out.print("Enter the second Diagonal: ");
            double Diagonal2kit = input.nextDouble();

            //formulae
            double kit = ((1/2) * Diagonal1kit * Diagonal2kit);

            //answer
            System.out.print("The Area of the Kite is: " + kit);
        }

    }
}

The output is:

Area Calculator

Enter the Shape: 

And when I enter the name nothing happens no code is run!