Update index.html

Fix

Author: Gmac4247

index.html

@@ -508,22 +508,23 @@ <h3 itemprop="name" style="margin:7px">Circumference of a Circle</h3>
 <span style="margin:12px" itemprop="abstract"><strong>The circumference of a circle is derived from its area algebraically by subtracting a smaller circle and dividing the difference by the difference of the radii.</strong></span>
 <div style="margin:12px" itemprop="step" itemscope itemtype="https://schema.org/HowToStep">
 <meta itemprop="position" content="1">
-<span itemprop="abstract">Let x represent the theoretical width of the circumference, which distinguishes it from the rest of the circle.
+<span itemprop="abstract">Let x represent the theoretical width of the circumference, which distinguishes it from the rest of the circle.</span>
 </div>
 <br><br>
 <div style="margin:12px" itemprop="step" itemscope itemtype="https://schema.org/HowToStep">
 <meta itemprop="position" content="2">
-<span itemprop="abstract">The difference between the shape of the straightened circumference and a quadrilateral is negligible.
+<span itemprop="abstract">The difference between the shape of the straightened circumference and a quadrilateral is negligible.</span>
 </div>
 <br><br>
 <div style="margin:12px" itemprop="step" itemscope itemtype="https://schema.org/HowToStep">
 <meta itemprop="position" content="3">
-<span itemprop="abstract">The length of the two shorter sides of the quadrilateral is x.
+<span itemprop="abstract">The length of the two shorter sides of the quadrilateral is x.</span>
 </div>
 <br><br>
 <div style="margin:12px" itemprop="step" itemscope itemtype="https://schema.org/HowToStep">
 <meta itemprop="position" content="4">
 <span itemprop="abstract">The length of the two longer sides is the area of the resulting ring divided by x.</span>
+</div>
 <br><br>
 <div itemprop="about" itemscope itemtype="https://schema.org/PropertyValue">
 <meta itemprop="description" content="Circumference derivation">
@@ -1833,7 +1834,7 @@ <h3 style="margin:7px">Trigonometry</h3>
 <meta itemprop="contentUrl" content="https://basic-geometry.github.io/trigonometry.png">
 </figure>
 <br>
-<span style="margin:12px" itemprop="abstract">In a right triangle the ratios between the sides and the angles are proportional.</p>
+<span style="margin:12px" itemprop="abstract">In a right triangle the ratios between the sides and the angles are proportional.</span>
 <br>
 <div style="margin:12px" itemprop="teaches" itemscope itemtype="https://schema.org/DefinedTerm" id="sine">
 <meta itemprop="inDefinedTermSet" content="Trigonometry">
@@ -1882,7 +1883,7 @@ <h4 itemprop="name">The Right Triangle Hypotenuse Theorem</h4>
 <br><br>
 <div itemprop="identifier" itemscope itemtype="https://schema.org/PropertyValue">
 <span itemprop="name">hypotenuse² </span>=
-<span itemprop="value"> leg<sub>1</sub>² + leg<sub>2</sub>²"></span>
+<span itemprop="value"> leg<sub>1</sub>² + leg<sub>2</sub>²</span>
 </div>
 </div>
 <div id="trigonometry-lookup">