diff --git a/11/c/4 - Secure the Perimeter.py b/11/c/4 - Secure the Perimeter.py
new file mode 100644
index 0000000..214cb2e
--- /dev/null
+++ b/11/c/4 - Secure the Perimeter.py	
@@ -0,0 +1,4 @@
+def trianglePerimeter(xA, yA, xB, yB, xC, yC):
+   return    distance2D(xA, yA, xB, yB
+         ) + distance2D(xB, yB, xC, yC
+         ) + distance2D(xC, yC, xA, yA)