Answer:
see explanation
Explanation:
sum the parts of the ratio, 1 + 2 + 3 = 6 parts
divide the sum of the angles in a triangle , 180° by 6 to find the value of one part of the ratio.
180° ÷ 6 = 30° ← value of 1 part of the ratio , the smallest , then
2 parts = 2 × 30° = 60°
3 parts = 3 × 30° = 90° , the largest angle
the angle sizes are 30° , 60° , 90°
smallest + largest = 30° + 90° = 120°