diff --git a/src/main/c/Calculator/calculator.c b/src/main/c/Calculator/calculator.c
index 2384f51..870f164 100644
--- a/src/main/c/Calculator/calculator.c
+++ b/src/main/c/Calculator/calculator.c
@@ -100,6 +100,12 @@ int main() {
                 result = cosine(angle);
                 printf("Cosine of %.2lf degrees: %lf\n", angle, result);
                 break;
+                case 13:
+                printf("Enter angle in degrees: ");
+                scanf("%lf", &angle);
+                result = tangent(angle);
+                printf("Tangent of %.2lf degrees: %lf\n", angle, result);
+                break;
                 case :
                 printf("Exiting...\n");
                 break;