In the triangle ABC, ∠ a = 80 degrees, the bisector of the outer angles of ∠ B and ∠ C intersects point O, and ∠ BOC?

In the triangle ABC, ∠ a = 80 degrees, the bisector of the outer angles of ∠ B and ∠ C intersects point O, and ∠ BOC?

If the outer angles of ∠ B and ∠ C are ∠ 1 and ∠ 2 respectively, then the bisector of ∠ 1 = ∠ a + ∠ C, ∠ 2 = ∠ a + ∠ B ≠ 1 + ∠ 2 = ∠ a + (∠ a + ∠ B + ∠ C) = 80 ° + 180 ° = 260 ° and Bo, CO is ∠ 1, the angle bisector of ∠ 2 ∠ CBO = (1 / 2) ∠ 1, ∠ BCO = (1 / 2) ∠ CBO + ∠ BCO = (1 / 2) (∠ 1 + ∠ 2) = 130 °∠ BOC = 180