What is 2pir^2 vs pir^2

Question

The question I have is relating to the area of a circle from a radio tower.

 

If I am using the equation Intensity = Power/Area why is it Intensity = Power/2piR^2

 

 

Answer 1

Area for one circle is

 

Area = piR²

 

 

If your area in the intensity formula is  2piR², then the radio tower must have 2 cross-sections that have circular shapes.