Answer:
(a)
(b) 
Step-by-step explanation:
It is given that
.
(a)
(b)
![[\because \sin x=\dfrac{1}{\csc x}]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Csin%20x%3D%5Cdfrac%7B1%7D%7B%5Ccsc%20x%7D%5D)

Therefore,
.
Answer

Solution
Simplify both sides of the equation.

We are left with d = 4+
Add

Hence, d = 
Answer:

Step-by-step explanation:
Because vertical angles are always equal, we want to solve
.
We can add 10 to both sides to get
.
We can subtract
from both sides to get
.
Lastly, we divide both sides by 20 to get
.
So,
and we're done!
The check is left as an exercise to the reader.
This is the answer!! Also I use Photomath to help with my hw!