Explanation:
the volume of such a cone is
pi×r² × h / 3
r is the radius of the ground circle, h is the straight inner height.
the radius is as always half of the diameter, so in our case
6/2 = 3 units.
so, the volume is
pi×3² × 11 / 3 = pi×9×11/3 = pi×3×11 = 33pi =
= 103.6725576... units³ ≈
≈ 103.7 units³