Respuesta :

Answer:

A = 81π cm²

Step-by-step explanation:

The formula for area of a circle is A = πr², where r is the radius.  The radius is half the diameter, so our radius for this problem is

18/2 = 9.    So the area is..

A = π(9²) = π(81)

  A = 81π cm²

Answer:81pi

Step-by-step explanation: