Added programs for Java projects

SIMPLE PROJECTS/AreaOfEqTriangle.java

@@ -0,0 +1,15 @@
+package com.KKDSA.Area;
+
+import java.util.Scanner;
+
+
+public class AreaOfEqTriangle {
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        System.out.println("Enter side:");
+        double side = sc.nextDouble();
+        double area = Math.sqrt(3)/4*side*side;
+        System.out.println("Area of equilateral triangle is " + area);
+
+    }
+}

SIMPLE PROJECTS/AreaOfRhombus.java

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+package com.KKDSA.Area;
+
+import java.util.Scanner;
+
+public class AreaOfRhombus {
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+
+        String option;
+        do {
+            System.out.println("Enter 1 if you have height and base");
+            System.out.println("Enter 2 if you have diagonals");
+            System.out.println("Enter 'x' to exit");
+            option = sc.nextLine();
+            switch (option) {
+                case "1" -> {
+                    System.out.println("Enter height: ");
+                    double height = sc.nextDouble();
+                    System.out.println("Enter base:");
+                    double base = sc.nextDouble();
+                    double area = base * height;
+                    System.out.println("The area of rhombus is " + area);
+                }
+                case "2" -> {
+                    System.out.println("Enter diagonal 1: ");
+                    double diagonal1 = sc.nextDouble();
+                    System.out.println("Enter diagonal 2: ");
+                    double diagonal2 = sc.nextDouble();
+                    double area = (0.5) * diagonal1 * diagonal2;
+                    System.out.println("The area of rhombus is " + area);
+                }
+                case "x" -> System.exit(0);
+                default -> System.out.println("Invalid option");
+            }
+        } while (true);
+    }
+}

SIMPLE PROJECTS/PerimeterOfSquare.java

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+package com.KKDSA.perimeter;
+
+import java.util.Scanner;
+
+public class PerimeterOfSquare {
+    public static void main(String[] args) {
+        do {
+            Scanner sc = new Scanner(System.in);
+            System.out.println("Enter 1 to find perimeter.");
+            System.out.println("Enter 2 to exit the code.");
+            int option = sc.nextInt();
+            if(option == 1) {
+                System.out.println("Enter side");
+                double side = sc.nextDouble();
+                double perimeter = Math.pow(side,2);
+                System.out.println("The area of circle is: " + perimeter);
+            } else if (option == 2) {
+                break;
+            }else{
+                System.out.println("Invalid option");
+            }
+        } while (true);
+    }
+}