Question

I need help with similar shapes please, I will post a picture in the comments as it includes a diagram. Basically I don't know where to start with this question. I also have the answer: 3.72cm

Answer 1

for similar figures the volumes change by the CUBE of the linear dimension

(for example if you double (x2) the height of the cone then its volume changes by x2^8 = x8)

so
\[\frac{ V }{ H ^{3} } = \frac{ v }{h ^{3} }\]

V= 128
H = 12
v= 42

so solve for h

(you can then get x)

Answer 2

Oh ok, will try that now.

Answer 3

I didnt actually get the right answer, could you show me the working?

Answer 4

once you have solved for h note that the question asks for x

Answer 5

I got 1.46 for h

Answer 6

the re-arranged equation is

\[h ^{3} = \frac{ H ^{3} \times v }{ V}\]

try again

Answer 7

ah this time h=23.81

Answer 8

But is that right?

Answer 9

evidently not

if you know ththe answer x= 3.72 then h = 12-3.72 = 8.28

Answer 10

Ok, thank you very much.

Answer 11

but - you already knew the answer

you need to understand how to get it

re-do your calculation (I think maybe you are using square root - but you need CUBEroot)

Answer 12

Yes, but I am short on time and need to move on to something else now. :)

Answer 13

I will keep that in mind next time I try, thanks.