Answer:
C) 905 km³
Explanation:
You want the volume of a cylinder 12 km in diameter and 8 km high.
Volume
The volume is given by the formula ...
V = πr²h
The radius is half the diameter, so is (12 km)/2 = 6 km. Then the volume is ...
V = π(6 km)²(8 km) ≈ 905 km³
The volume of the cylinder is about 905 km³.