<PRE><B>Question 678312</B>


(a+15) + (7a) + (7a) = 180


a+15 + 7a + 7a = 180


15a+15 = 180


15a = 180-15


15a = 165


a = 165/15


a = 11


a+15 = 11+15 = 26


7a = 7(11) = 77


So in the end, 


a = 11


a+15 = 26


7a = 77


Therefore, the three angles are 26, 77, and 77 degrees.


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