Solving for exterior angle measures
what is the measure of ∠abd?

(4n + 6)° = (2n)° + 60°    [since external angle is equal to sum of two internal                                              angles]

(4n + 6)° = (2n)° + 60° 
4n - 2n = 60 - 6
       2n = 54
         n = 27

Since n = 27 and  ∡ ABD = (4n + 6)°
 
∡ ABD = [4(27) + 6]°
            = (108 + 6) °
            = 114°