Acircle has a circumference of 6. what is it's diameter? you!

Pls! does anybody know a shortcut for answering these types of questions in the future?

Atriangle with all sides of equal length is a/an triangle. a. right b. scalene c. equilateral d. isosceles

Tyler enjoys the fish so much that after his birthday his family decides to take him to a famous aquarium a tank at the aquarium is similar to his tank with the scale factor of 8 how many times greater is the volume of the tank at the aquarium than the volume of tyler tank