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 12 m. The inner edge of the sidewalk is a circle with a radius of 8 m. 
Write and simplify an expression for the exact area of the sidewalk.
Find the approximate area of the sidewalk. Use 3.14 to approximate π.
                                             
                                          
                                          
                                        
											 
			                  