The formula for the volume of the cylinder goes as follows:
pi • h • r^2
The radius in your case is 3mm while the height is 4mm
Let’s plug in those values
pi • (4mm) • (3mm)^2
pi • (4mm) • (9mm^2)
36mm^3 pi
Substitute 3.14 for pi
36mm^3 (3.14)
113mm^3
So, b