diff --git a/.github/ISSUE_TEMPLATE/contribution.md b/.github/ISSUE_TEMPLATE/contribution.md
index fd6a3834..377f463e 100644
--- a/.github/ISSUE_TEMPLATE/contribution.md
+++ b/.github/ISSUE_TEMPLATE/contribution.md
@@ -2,8 +2,10 @@
 - Fork this [repo](https://github.com/swaaz/basicprograms)
 - Clone it using command :
 <pre> $ git clone paste_the_copied_url.</pre>
+- Open folder "basicprograms"  :
+<pre>$ cd basicprograms</pre>
 - Open folder "C/Python"  :
-<pre>$ cd filder_name</pre>
+<pre>$ cd folder_name</pre>
   eg:cd C
 - Create new branch :
 <pre> $ git branch new_branch_name</pre>
diff --git a/C/Program-43/program.c b/C/Program-43/program.c
new file mode 100644
index 00000000..35e5b447
--- /dev/null
+++ b/C/Program-43/program.c
@@ -0,0 +1,45 @@
+
+// C program for printing the hollow triangle pattern 
+  
+#include <stdio.h> 
+  
+// Function for printing pattern 
+void pattern(int N) 
+{ 
+    int i, j, k = 0, space = 1, rows = N; 
+  
+    // For printing stars 
+    for (i = rows; i >= 1; i--) { 
+        for (j = 1; j <= i; j++) { 
+            printf("*"); 
+        } 
+        if (i != rows) { 
+            // for printing space 
+            for (k = 1; k <= space; k++) { 
+                printf(" "); 
+            } 
+  
+            // increment by 2 
+            space = space + 2; 
+        } 
+        for (j = i; j >= 1; j--) { 
+            if (j != rows) 
+                printf("*"); 
+        } 
+        printf("\n"); 
+    } 
+    printf("\n"); 
+} 
+  
+// Driver code 
+int main() 
+{ 
+  
+    // Get N 
+    int N = 6; 
+  
+    // Print the pattern 
+    pattern(N); 
+  
+    return 0; 
+} 
diff --git a/C/README.md b/C/README.md
index 5281951b..5076d0b7 100644
--- a/C/README.md
+++ b/C/README.md
@@ -41,4 +41,11 @@
 | Program-37 | Program to find the fibonacci sequnce using recursion |
 | Program-38 | Program to find the factorial of a number using recursion |
 | Program-39 | Program to find the GCD of a number using recursion |
+| Program-40 | Program to find the ackerman of given two numbers|
+| Program-41 | Program to find sum of two numbers without using any operator |
+| Program-42 | Program to print Floyd’s triangle Without using a temporary variable and with only one loop |
+| Program-43 | Program for printing the hollow triangle pattern |
+| Program-44 | Program for implementation of the approach |
+| Program-45 | Program to illustrate the above given pattern of numbers. |
+
 
diff --git a/C/program-40/program.c b/C/program-40/program.c
new file mode 100644
index 00000000..f48a3382
--- /dev/null
+++ b/C/program-40/program.c
@@ -0,0 +1,22 @@
+/*Write a C program to find the Ackermann of 2 Numbers*/
+
+#include<stdio.h>
+int ack(int m,int n)
+{
+    if(m==0)
+      return n+1;
+    else if(m!=0 && n==0)
+      return ack(m-1,1);
+    else if (m!=0 && n!=0)
+      return ack(m-1,ack(m,n-1));  
+}
+
+int main()
+{
+    int a,b,c;
+    printf("Enter 2 Elements:\n");
+    scanf("%d%d",&a,&b);
+    c=ack(a,b);
+    printf("Ackermann(%d,%d)=%d",a,b,c);
+    return 0;
+}
diff --git a/C/program-41/program.c b/C/program-41/program.c
new file mode 100644
index 00000000..2cd3cd17
--- /dev/null
+++ b/C/program-41/program.c
@@ -0,0 +1,14 @@
+/*To find sum of two numbers without using any operator*/
+#include<stdio.h> 
+
+int add(int x, int y) 
+{ 
+	return printf("%*c%*c", x, ' ', y, ' '); 
+} 
+
+// Driver code 
+int main() 
+{ 
+	printf("Sum = %d", add(3, 4)); 
+	return 0; 
+} 
diff --git a/C/program-42/program42.c b/C/program-42/program42.c
new file mode 100644
index 00000000..5a6154b0
--- /dev/null
+++ b/C/program-42/program42.c
@@ -0,0 +1,17 @@
+/*C Program to print Floyd’s triangle*/
+// Without using a temporary variable and with only one loop 
+#include<stdio.h> 
+void floyd(n){ 
+    int i,j=1; 
+    for (i=1;i<=(n*(n+1))/2;i++){ 
+        printf("%d ",i); 
+        if(i==(j*(j+1))/2){ 
+            printf("\n"); 
+            j++; 
+        } 
+    } 
+} 
+  
+int main(){ 
+    floyd(6); 
+} 
diff --git a/C/program-44/program.c b/C/program-44/program.c
new file mode 100644
index 00000000..24dbbcb7
--- /dev/null
+++ b/C/program-44/program.c
@@ -0,0 +1,48 @@
+// C implementation of the approach 
+#include <stdio.h> 
+
+// Function to print the desired 
+// Alphabet Z Pattern 
+void alphabet_Z_Pattern(int N) 
+{ 
+	int index, side_index, size; 
+
+	// Declaring the values of Right, 
+	// Left and Diagonal values 
+	int Top = 1, Bottom = 1, Diagonal = N - 1; 
+
+	// Loop for printing the first row 
+	for (index = 0; index < N; index++) 
+		printf("%d ", Top++); 
+
+	printf("\n"); 
+
+	// Main Loop for the rows from (2 to n-1) 
+	for (index = 1; index < N - 1; index++) { 
+
+		// Spaces for the diagonals 
+		for (side_index = 0; side_index < 2 * (N - index - 1); 
+			side_index++) 
+			printf(" "); 
+
+		// Printing the diagonal values 
+		printf("%d", Diagonal--); 
+
+		printf("\n"); 
+	} 
+
+	// Loop for printing the last row 
+	for (index = 0; index < N; index++) 
+		printf("%d ", Bottom++); 
+} 
+
+// Driver Code 
+int main() 
+{ 
+	// Size of the Pattern 
+	int N = 5; 
+
+	alphabet_Z_Pattern(N); 
+
+	return 0; 
+} 
diff --git a/C/program-45/program.c b/C/program-45/program.c
new file mode 100644
index 00000000..a19e4af8
--- /dev/null
+++ b/C/program-45/program.c
@@ -0,0 +1,37 @@
+
+// C program to illustrate the above given pattern of numbers. 
+#include<stdio.h> 
+   
+int main() 
+{ 
+      int n = 5, i, j, num = 1, gap; 
+   
+      gap = n - 1; 
+   
+      for ( j = 1 ; j <= n ; j++ ) 
+      { 
+          num = j; 
+   
+          for ( i = 1 ; i <= gap ; i++ ) 
+              printf(" "); 
+   
+          gap --; 
+   
+          for ( i = 1 ; i <= j ; i++ ) 
+          { 
+              printf("%d", num); 
+              num++; 
+          } 
+          num--; 
+          num--; 
+          for ( i = 1 ; i < j ; i++) 
+          { 
+              printf("%d", num); 
+              num--; 
+          } 
+          printf("\n"); 
+   
+      } 
+   
+      return 0; 
+}