At a zoo, the lion pen has a ring-shaped sidewalk around it. The outer edge of the sidewalk is a circle with a radius of 11 m. The inner edge of the sidewalk is a circle with a radius of 9 m.

(Q. 1)
Write and simplify an expression for the exact area of the sidewalk.
(Q. 2)
Find the approximate area of the sidewalk. Use 3.14 to approximate π.