diff --git a/src/pages/traits/traits.md b/src/pages/traits/traits.md
index 0dc38cf..02ff66c 100644
--- a/src/pages/traits/traits.md
+++ b/src/pages/traits/traits.md
@@ -282,8 +282,8 @@ sealed trait Rectangular extends Shape {
   def width: Double
   def height: Double
   val sides = 4
-  override val perimeter = 2*width + 2*height
-  override val area = width*height
+  override def perimeter = 2*width + 2*height
+  override def area = width*height
 }
 
 case class Square(size: Double) extends Rectangular {