find thr volume of the iron usrd to make a hollow cylinder of hright 9cm and whose internal and external radius are 21cm and 28cm respectively​

sorry I don't know the answer to

Volume of iron used is 58982cm

Step-by-step explanation:

For hollow cylinder,

\bold{Height=9cm}Height=9cm

\bold{Internal \ radius=21cm}Internal radius=21cm

\bold{Externa \ radius=28cm}Externa radius=28cm

volume \: of \: cylinder = \pi \times {r}^{2} \times h \:volumeofcylinder=π×r

2

×h

\bold{Volume \ of \ cylinder \ with \ hollow \ part}Volume of cylinder with hollow part

\bold{=\frac{22}{7}×28^2×9}=

7

22

×28

2

×9

\bold{=22×4×28×9}=22×4×28×9

\bold{=71456cm^3}=71456cm

3

\bold{Volume \ of \ hollow \ part}Volume of hollow part

\bold{=\frac{22}{7}×21^2×9}=

7

22

×21

2

×9

\bold{=22×3×21×9}=22×3×21×9

\bold{=12474cm^3}=12474cm

3

\bold{Volume \ of \ iron \ used=}Volume of iron used=

\bold{Volume \ of \ cylinder \ with \ hollow \ part}Volume of cylinder with hollow part

\bold{- Volume \ of \ hollow \ part}−Volume of hollow part

{=71456-12474}=71456−12474

{=58982cm^3}=58982cm

3

\bold\red{Volume \ of \ iron \ used \ is \ 58982cm^3}Volume of iron used is 58982cm

3

lol

step-by-step explanation:

which would be true for stem changing verbs?

they have a consistent spelling change in the stem of the verb.

what is different about the verb “venir” as compared to other stem-changing verbs?

only the third person forms have a stem change.

which of the following could not be considered a “stem-changing” verb?

querer

which of the following would not be condsidered an event?

desfile

what word could be used in response to the following?

¿qué quieres comprar?

quero

what word could be used in response to the following?

¿dónde uds. pueden ir?

vamos  

ellos ir al centro comercial.

yo comprar un vestido.

pedimos

dónde tú?

dormes

step-by-step explanation: