Explanation:
the volume of a cylinder (as any regular 3D object) is
base area × height
since the base area of a cylinder is the area of a circle, that means
pi×r² × height
in our case we have
4860 = pi×r²×180
27 = pi×r²
r² = 27/pi
r = sqrt(27/pi)
FYI :
sqrt(27/pi) = 2.931615071... cm