A man enters a tall tower, needing to know its height. He notes that a long pendulum

Question:

A man enters a tall tower, needing to know its height. He notes that a long pendulum extends from the ceiling almost to the floor and that its period is 12.0 s.
(a) How tall is the tower?
(b) What If? If this pendulum is taken to the Moon, where the free-fall acceleration is 1.67 m/s2, what is its period there?