Update orth_proj.md

Author: longye-tian

lectures/orth_proj.md

@@ -193,7 +193,7 @@ In what follows we denote this operator by a matrix $P$
 The operator $P$ is called the **orthogonal projection mapping onto** $S$.
 
 ```{figure} /_static/lecture_specific/orth_proj/orth_proj_thm2.png
-:scale: 75%
+:scale: 65%
 
 ```