In triangle FGH, m∠F is 92°, m∠G is 47°, and m∠H is 41°. The exterior angles of triangle FGH are ∠J, ∠K, and ∠L, and they are adjacent to ∠F, ∠G, and ∠H, respectively.
since angle L is adjacent to angle H which equals 41, you can subtract 41 from 180 (because adjacent supplementary angles must equal 180) this gives you an answer of 139
