Okay so a couple of things to know to best solve this problem
1) all angles in a triangle add to 180
2) a straight line the angles above it equal 180 and the angles below it add to 180
3) vertical angles are equal (vertical angles are angles that make an X the opposite angles are called vertical angles)
Answer:
big
Step-by-step explanation:
2
Answer: First Option
Walter needs to make at least 5 more cookies but no more than 40

Step-by-step explanation:
If we call x the number of cookies that Walter needs to make, then we know that the amount of cookies will be:

Then this amount must be greater than or equal to 20 and must be less than or equal to 55 then.
and 
This is:

We solve the inequality for x.

Then the amount of cookies that Walter must make must be greater than or equal to 5 and less than or equal to 40
Well CD and CB are both equal to each other because they’re the same angles , it’s a reflection