Answer:
b = 65 degrees
Explanation:
As we can see, the line that angle b and 115 deg correspond to is a straight line. A straight line always measures at 180 deg.
Because of this principle, we know that:
![115+ b = 180](https://img.qammunity.org/2023/formulas/mathematics/college/u7skzzqczimr4mvs15hawxdy0e00zk8kt3.png)
We can simplify this one variable equation now:
![b=180-115\\](https://img.qammunity.org/2023/formulas/mathematics/college/fnuuxrwxfewmtyv02igbmks85stgufjsvj.png)
Now solve:
![b=65](https://img.qammunity.org/2023/formulas/mathematics/college/ggo2izsz0obsw94got2pdcqm0lldngx6vu.png)
And this makes sense. Just by eyeballing the angle, we can see that it is under 90 degrees.
So, b = 65 degrees