Respuesta :
The circumference will be approximately 131.95mm. Hope this helps :)
Circumference of a circle = 2πR & since R= 1/2 of Diameter, then R =21 mm
& the Circumference = 2π.(21) = 42π mm or 132 mm
& the Circumference = 2π.(21) = 42π mm or 132 mm