Answer: the height would be 15
Step-by-step explanation:
v= pi*radius^2*height
1215pi mm= pi*9^2*height
1215pi mm= pi*81*height
(divide by pi on both sides, which isolates pi on both sides)
1215 mm= 81*height
(divide by 81 on both sides, which would isolate 81 on the right side of the equation)
1215/81= 15= height