Answer:
d. 5 cm
Step-by-step explanation:
You want the height of a cone with base area 51 cm² and volume 85 cm³.
The volume of the cone is given by ...
V = 1/3Bh
where B is the base area and h is the height.
Then the height is ...
3V/B = h
3(85 cm³)/(51 cm²) = h = 5 cm
The height of the cone is 5 cm, choice D.