If the angle ∠DGB is twice the angle ∠DBG. find the angle ∠CAG.......
180-60 = 120
120/3 = 40 = DBG
40*2 = 80 = DGB
Thus CGA is also 80 degrees.
It appears that the triangles are similar so CAG pairs up with DBG thus it's 40.
+1006 
