diff --git a/experiment/theory.md b/experiment/theory.md
index 7292ea8..aafafdc 100644
--- a/experiment/theory.md
+++ b/experiment/theory.md
@@ -242,7 +242,6 @@ The circuit configuration of AC voltage controller with R-L load is shown in Fig
   <img src="images/th18.png" height="750px">
   
 Fig. 4. Typical waveforms with R-L load (α<90&#176;).
-
 </center>
 
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