Respuesta :

Answer:

A = 81π cm²

Step-by-step explanation:

The area (A) of the cross section is calculated as

A = πr² ( r is the radius )

Find r by using the given circumference.

Given the circumference is 18π and circumference (C) is

C = 2πr = 18π ( divide both sides by 2π )

r = 9, thus

A = π × 9² = 81π cm²