Verified answer

Answer:

(1) 3.5cm

Step-by-step explanation:

Volume of cone = πr²h/3

231cm³ = (18cm×3.14×r²)/3

Solve it, you get

r² = 1226cm²/100

r = 3.5 cm

Answer:

3.5

Step-by-step explanation:

volume of the cone=231cm^3

or, 1/3πr^2h =231cm^3

or, 1/3*22/7*r^2*18=231cm^3

or, 22/7*r^2*6=231cm^3

or, 132/7*r^2=231cm^3

or, 132*r^2=231*7cm^3

or, r^2=1617/132cm^2

or. r^2=12.50cm^2

or, (r)^2=(3.5cm)^2

:r = 3.5cm