diff --git a/rules/S4487/csharp/rule.adoc b/rules/S4487/csharp/rule.adoc
index ecccd1c528..f27efe8adf 100644
--- a/rules/S4487/csharp/rule.adoc
+++ b/rules/S4487/csharp/rule.adoc
@@ -13,13 +13,13 @@ public class Rectangle
   {
     this.length = length;
     this.width = width;
-  }
+  } 
 
   public int Surface
   {
     get
     {
-      return length * width;
+      return length * length;
     }
   }
 }
@@ -56,4 +56,4 @@ public class Rectangle
 
 * CWE - https://cwe.mitre.org/data/definitions/563[CWE-563 - Assignment to Variable without Use ('Unused Variable')]
 
-include::../rspecator.adoc[]
\ No newline at end of file
+include::../rspecator.adoc[]