Answer:
30°
Step-by-step explanation:
Let the measure of missing angle be x°
[tex] \therefore \: x + 80 \degree + 70 \degree = 180 \degree \\ \therefore \: x + 150 \degree = 180 \degree \\ \therefore \: x = 180 \degree - 150 \degree \\ \therefore \: x = 30 \degree [/tex]