Were is the angel? I will need to see the angel:D
I’d just say that you cannot know a method they have not thought you because they are your teachers and are expected to teach you this not to teach yourself
Step-by-step explanation:

Value 1:
r = 5ft, h = 10ft. Substitute:

Value 2:
r = 2in, h = 4in. Substitute:

Value 3:
r = 6m. Substitute:

Answer: 851.44
Step-by-step explanation: try to do the math
Combined like terms than subtract with system of equations