Find the area and circumference of 16.1cm

If 16.1cm is a radius of circle:
# Area= Pi X R{2}
           = 3.141592654 X 16.1 square
           = 814.3 cm square
# circumference= Pi X 2 X R
                          = 3.141592654 X 2 X 16.1
                          = 101.2 cm
# if 16.1 is a diameter:
#Area= Pi X D/2 square
          = 3.141592654 X 16.1 divide by 2 square
          = 203.6 cm square
#Circumference= Pi X D
                          = 3.141592654 X 16.1
                          =50.6 cm

That's it it. a bit long cuz I dun know what exactly what they given Radius or Diametre.