Respuesta :

Answer:

1. 90

2.60

3.30

4. 40

5. 80

6. 60

7. 30

8. 30

9. 120

Total for all triangles=180

Step-by-step explanation:

In all the problems, you have to solve for y.  This can be done because the three angles are supplementary  For example, in the first diagram, you have:

3y+2y+y=180

6y=180

y=30

It's fairly easy to solve from there.  Just more multiplying and subtracting.