Formula to find the area: A=πr^2
Formula to find circumference: C=2πr
Diameter is twice the length of the radius, so if you're given diameter of 3, the radius is half of that, which that would be 1.5.
A=π(1.5)^2 A= 3.14x1.5^2 = 7.065
Don't forget to round that and that becomes 7.07.
C=2π(1.5) C= 2x3.14x1.5 = 9.42
That stays as it is.
Area= 7.065
Circumference= 9.42