Answer:
1. 17.73 or 17
or 
2. 5.32 or 5
or 
Step-by-step explanation:
Each one is correct trust me ;)
We want to rewrite the following equation

With d as a function of the other terms. Let's start by subtracting n from both sides.

Now, let's divide both sides by 9.

And this is our final answer.
180-55-80=45
so it is 45 degree because triangle sun of all the angle is 180
What is the questions that you need answered?