The area of a cicle has the units of cm², so this is what you are trying to find.
So since the equation for area of a circle is:
Area = π × r² , where r = radius of cicle
To find the area of your circle,
Area = π × (16 cm)²
Area = π × 256 cm²
Area = 804.248 cm² (rounded up to 3 decimal places)