GCSE Maths Question

zpos · 2 Jun 2006 at 21:31

Hi, this is doing my head in. It's for my daughter and I have no idea how to work it out. It doesn't seem to follow any logic.

Can anyone help? It's for the higher tier GCSE maths (obviously) which she has on Monday!

Thanks,

z

ElRazur · 2 Jun 2006 at 21:33

There is a simple formula iirc but im rubbish at maths, hopefully someone will shed more light on it for you.

zpos · 2 Jun 2006 at 21:37

ElRazur said:
There is a simple formula iirc but im rubbish at maths, hopefully someone will shed more light on it for you.

Hope so, this is some dark corner of maths that I've not needed to use for well over 20 years!

the_brainaic · 2 Jun 2006 at 21:38

CE is 12cm and CB is 9cm.

ballistic · 2 Jun 2006 at 21:41

ratio 1.5

Rich1988 · 2 Jun 2006 at 21:41

hypotonuse something or other, cant remember the exact thing :rolleyes:

ElRazur · 2 Jun 2006 at 21:41

the_brainaic said:
CE is 12cm and CB is 9cm.

How did you arrive at that? I have been trying behind the screen and i can only manage 5.5 for the first one...

zpos · 2 Jun 2006 at 21:42

the_brainaic said:
CE is 12cm and CB is 9cm.

Can I please have the working out sir and anything else which will unravel this mystery.

z

ballistic · 2 Jun 2006 at 21:42

Rich1988 said:
hypotonuse something or other

no

13.5/1.5
8*1.5

the_brainaic · 2 Jun 2006 at 21:42

Ah, you might want a method. The two trianges are similar as the angles are all the same size, so the only difference is the size of the triangles. They are proportional to each other, so the top triangle has lengths 2/3 as long as the lower triangle. Then just visualise them on top of each other, and multiply by 2/3 or multiply by 3/2 as needed.

Rich1988 · 2 Jun 2006 at 21:43

ballistic said:
no

I am sure its got something to do with that because its just two equalatral *sp triangles

ElRazur · 2 Jun 2006 at 21:45

I swear to god this is hypothenouse triangle related stuff.

Rich1988 · 2 Jun 2006 at 21:47

ElRazur said:
I swear to god this is hypothenouse triangle related stuff.

see! what I said

Edit HA!

The square of the hypotenuse is equal to the sum of the squares of the two shorter sides

Pine · 2 Jun 2006 at 21:48

Rich1988 said:
I am sure its got something to do with that because its just two equalatral *sp triangles

How on earth can they be equilateral, the two given lengths are different?

zpos · 2 Jun 2006 at 21:48

Ok, got it now.

Blimey, my head really hurts.

Thanks for everyone for their help including ElRazur purely for great entertainment value!

z

Conrad11 · 2 Jun 2006 at 21:49

Its to do with similar trianges and the ratio of the sides i believe....

CE =

(9/6) * 8 = 12cm (I think)

That should help you work out the rest

ballistic · 2 Jun 2006 at 21:49

ElRazur said:
I swear to god this is hypothenouse triangle related stuff.

find me the 90 degree angle then..

ElRazur · 2 Jun 2006 at 21:50

zpos said:
Ok, got it now.

Blimey, my head really hurts.

Thanks for everyone for their help including ElRazur purely for great entertainment value!

z

Do you mind sharing with us please.

Rich1988 · 2 Jun 2006 at 21:50

no 90 degree angles

kip02 · 2 Jun 2006 at 21:51

I don't know if it has anything to do with it, but just had a look in one of my gcse maths books that i still have lying around 2 years later and it has a help guide at the top of one of the pages. Don't know if it is the same thing as i wasn't too good at maths. I only done intermediate, so it mite be a scaled down version or mite not be the same thing at all of which ignore me. lol