Update index.html

Author: Gmac4247

index.html

@@ -1807,8 +1807,8 @@ <h2 itemprop="name" style="margin:7px">Trigonometry</h2>
 <br>
 <br>
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-<div itemref="area">
-<section itemscope itemtype="http://schema.org/CreativeWork" id="triangle">
+<div id="triangle">
+<section itemscope itemtype="http://schema.org/CreativeWork" itemref="area">
 <h3 itemprop="name" style="margin:7px">Area of a Triangle</h3>
 <br>
 <p itemprop="description" style="margin:12px">The area of a triangle equals half of the area of a rectangle with a width equal to the base of the triangle and length equal to the height of the triangle.