If 3/4 = x/8 then x is equal to what

When turned about its axis of rotation, which shape could have created this three-dimensional object?

Can someone me with these two circle theorem questions asap?

Question 5 of 10 2 points if a population is a sample of the population could be a. registered voters; all citizens o o b. baptists; all religious people o c. people who purchased shoes; all customers o d. the entire school faculty; math teachers