Answer:
See if this will help,
https://www.pmschools.org/site/handlers/filedownload.ashx?moduleinstanceid=701&dataid=3612&FileName=2015%20triangle%20proofs%20answers.pdf
The volume will increase as each layer is added because you are adding more to that certain shape
I’m pretty sure This rounds to 900
If the two angles are supplementary, they must equal 180 degrees