Question

A cone has a base radius of 2 millimeters and a height of 24 millimeters.

What is the volume of the cone?

A.
16π mm3

B.
96π mm3

C.
384π mm3

D.
32π mm3

Answer 1

do you know the formula for the volume of a cone ?

Answer 2

yea v=1/3TTr^2h

Answer 3

ok,
\[ V = \frac{1}{3} \pi r^2 h \]
replace h with 24
replace r with 2
can you do that ?

Answer 4

yeah

Answer 5

can you post it ?

Answer 6

V=1/3TT(2)^2(24)

Answer 7

remember order of operations. we do exponents first
what is 2^2 ?

Answer 8

4

Answer 9

so replace 2^2 with 4
V=1/3TT(4)(24)

that says multiply 1/3 * pi * 4 * 24
we can multiply in any order. put the pi to the aside, and do the numbers

Answer 10

I would first do 1/3 * 24 (because you get a nice number)

Answer 11

V=1/3TT*4*24
v=1/3*96
V=96/3TT

Answer 12

IS that right

Answer 13

if you mean
\[ V= \frac{96}{3} \pi\]
yes.
but 3 divides evenly into 96
(I would have done 24/3 = 8 first, and then 8*4= 32)
but you can do it this way
what is 96/3 ?

Answer 14

okay thankyou

Answer 15

what did you get ?

Answer 16

32

Answer 17

yes, so
\[ V= 32 \pi\]
btw, the reason they did not multiply pi * 32
is because pi is
3.14159265358979323846…(goes on forever)
and rather than pick some "rounded version" such as 3.14
they leave it 32 pi
then if you want a number, you use pi to the accuracy you want.

Answer 18

okay thanks for the help