I did out all my work but it got deleted. Hope you don't mind just answers.
5) 10
6) 32
7) 64 pi
8) A=64 pi C=16 pi
9) A=110.25 pi C=21 pi
10) A=1024/pi C=64
11) L=4sqrt(5) or about 9 midpoint is (1,4)
12) L=sqrt(37) or about 6 midpoint is (-1,-3.5)
Sorry I couldn't show work, hope this helps :)
