Answer:
∠ 1 = 72° , ∠ 2 = 60° , ∠ 3 = 48°
Step-by-step explanation:
The 3 angles lie on a straight line and sum to 180°
sum the parts of the ratio , 6 + 5 + 4 = 15 parts
Divide 180° by 15 to find the value of one part of the ratio
180° ÷ 15 = 12 , then
∠ 1 = 12 × 6 = 72°
∠ 2 = 12 × 5 = 60°
∠ 3 = 12 × 4 = 48°
