Answer:
D 9m 4m because 9 divided by 2 is 3 and 4 divided by 2 is 2 and that's us you answer.
The radius is 8, just divide by 2
I'm assuming you mean triangle angles?
If so, all angles add up to 180 so combine them and set them equal to 180.
51+82+5x+2=180
135+5x=180
5x=45
x=9