②∠B=∠C=2∠A, then ∠ C = (72).

③∠A:∠B:∠C=2:2:5, then ∠ C = (100).

④ If ∠A=∠B, one angle is 50, and the other two angles are (50 and 80) or (75 and 75).

⑤ ∠ A = 105, ∠ B-∠ C = 15, then ∠ C = (30).

⑥ If ∠ A+∠ B-∠ C = 50, ∠ C = (65).

⑦ If ∠ A+∠C = 100 and ∠B=2∠A, the number of ∠C is (60).

(Note: I thought about it myself, and I didn't copy it. Hope to adopt! ! )