About how many radii go around half of a circle?

Pls never taught i’m really confused and i rlly need

What is the value of n in the equation -1/2(2n+4)+6=-9+4(2n+1)

Which of the following are independent events? a) knowing that it is going to rain tomorrow, and bringing an umbrella to schoolb) knowing that you have to get up early tomorrow, and going to bed before 9 p.mc) knowing that it is going to rain tomorrow, and going to bed before 9 p.md) knowing that you have a test in school tomorrow, and studying thw night before