Answer:
40°, 60°, 80°
Explanation:
sum the parts of the ratio , 2 + 3 + 4 = 9 parts
the sum of the 3 angles in a triangle = 180° , then
180° ÷ 9 = 20° ← value of 1 part of the ratio , then
2 parts = 2 × 20° - 40° = ∠ A
3 parts = 3 × 20° = 60° = ∠ B
4 parts = 4 × 20° = 80° = ∠ C