Answer:
15° , 45°, 120°
Step-by-step explanation:
sum the parts of the ratio, 1 + 3 + 8 = 12 parts
the sum of the 3 angles in a triangle = 180° , then
180° ÷ 12 = 15° ← value of 1 part of the ratio, then
3 parts = 3 × 15° = 45°
8 parts = 8 × 15° = 120°
the 3 angles are 15° , 45° , 120°
