A: ,
A comma seperates two ideas to make it a compound sentence and can link two ideas together. A plus is for math, and a period is used to end a sentence
Greater than because they are negative

Thickness of the book is ~
Refer to the attachment for solution ~
Hey there :) I'm pretty sure that your answer is D) ∠S ≅ <span>∠Y because corresponding angles of similar triangles are congruent.
I think that it is the answer because if you shift your paper around, and look at the angles from different views, you can tell that angles S and Y are congruent, or the same, because of the way that both angles are at the end of the longer sides of both triangles.
So, your answer is D!
~Hope this helped!~</span>