Question 1196429
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<font color=red>Co</font>mplementary angles form a 90 degree <font color=red>co</font>rner. I've highlighted the "co" to help remember the connection.  


(3r-4)+(r+30) = 90
(3r+r)+(-4+30) = 90
4r+26 = 90
4r = 90-26
4r = 64
r = 64/4
r = 16
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