Update index.html

Author: Gmac4247

index.html

@@ -141,7 +141,7 @@ <h2 itemprop="name" style="margin:7px">Key Points:</h2>
 <br>
   <div itemprop="itemListElement" itemscope itemtype="https://schema.org/ListItem">
     <meta itemprop="position" content="2">
-    <a href="#circumference" style="margin:7px">
+    <a href="#circumference" itemprop="item" style="margin:7px">
       <span itemprop="name">Circumference = 6.4 × radius</span>
     </a>
     <p itemprop="description" style="margin:12px">