I NEED HELP ON MATH HW

Question: Suppose a metal ring could be placed around earth at the equator. The radius of Earth is 6378.1km
A. How long is the metal ring?
B. If the length of the metal ring is increased by 1km, would you be able to 1. crawl under the ring, 2. walk under the ring. 3. drive in a school bus under the ring? Explain

assuming part A of your question is asking for the length all the way around the ring then that would be the circumference found as C = 2*pi*r r being the radius

so take

2*pi*6378.1 and you get your answer

part B you have to work backwards starting with your answer from part A

first obviously you have to add 1 to your answer from part A to account for that extra 1 km

then you have to solve for the radius of the ring

since c = 2*pi*r

r = c/(2*pi)

so you will find the radius of the ring by taking
r = (answer from part A)/(2*pi)

to determine the space between the ring and the surface of the earth you have to subtract the radius of the earth from the radius of the ring that you just found

I dont know stuff like that but thanks for the easy points :P