http://img861.imageshack.us/i/page741.jpg/
Can some one help me please!

Question

dumbcow · Answer

For #20 volume of a cone is 1/3 volume of cylinder
cylinder: V=pir^2*h
cone: V = 1/3pi*r^2*h
so 2/3 of the space is outside cone but inside cylinder

#21 im not quite sure about what dimensions the numbers given in figure refer to?

anonymous · Answer

the base and the height of the cone is the same cylinder?

anonymous · Answer

20 is look the smae to me

dumbcow · Answer

yes, it says they share the same base and height

anonymous · Answer

21) I think the question is find volum a pyramid, I can fid it , but subtrac the cone it hard to tell how much the cone is overlap

dumbcow · Answer

it says the base of cone is inscribed in the square or base of pyramid so there is no overlap, its like the 2 bases are pressed together

anonymous · Answer

Can you show me how to find Volum?

anonymous · Answer

it mean find volum of cone?

dumbcow · Answer

ok volume of cone is 1/3*pi*r^2*h
slant height = 12
all we need is the radius.
do you know what the 8 and 10 refer to?

anonymous · Answer

the base is 10 square is mean radius square is 5 ? and use 5 to find Valume of cone?

anonymous · Answer

1/3*pi*5^2*h
I know how to find the h

dumbcow · Answer

oh ok i see it now.
yes you are correct
just use pytharean theorem to get height

anonymous · Answer

12^2-5^2=10.9 the h of cone ,am I righ?

dumbcow · Answer

correct

anonymous · Answer

OK. thank

dumbcow · Answer

your welcome