Respuesta :

choixongdong
r = d/2 = 42/2 = 21

Area = πr^2 
Area = π(21^2)
Area = 441π mm^2

MrSmooth107
The area of a circle is defined as 3.14r^2
If the diameter is 42mm, the radius, r, is 21mm
Plug 21 into the equation
3.14(21)^221 squared is 4413.14(441)=1,385.4
The are of your circle is 1,385.4 mm^2
Hope this helps! Can I get Brainliest if it does?