How do you find the circumference and area ? ( what formula do you use)

Circumferece=pi times radius times 2
or
circumference=pi times diameter

remember that radius only goes from the middle of the circle to the outside whiel the diameter goes from 1 side to the other, passing through the middle
and
diameter/2=radius

area=pi times radius^2

1. radius=6
circumference=pi tiimes 6 times 2=12pi in
area=pi times 6^2=36pi square inches

2. radius is 3
circumfernce=pi times 3 times 2=6pi in
area=pi times 3^2=9pi square units

3., the gave us diameter
circumfernce=6 times pi=6pi in
the radius is half of the diameter, or 6/2 or 3
area=pi times 3^2==9pi=9pi square inches