MATHS help thanks

[PlKEY-ARMY]

hey guys,

just a maths question

havent done Pythagoras like a year so i thought i better look it up again havent got any school books or anything so checked bitesize bbc site.


Calculate the lengths marked with letters and type them in the boxes. Give your answers to 1 decimal place.
http://www.bbc.co.uk/schools/gcsebitesize/img/ma10032.gif

i got them 3 wrong :eusa_wall
lets take first one for example
i did the 7x7 then 12x12 then add totals together which gives 193 so i fine the square root and and it is "13.8924439894498" so at the top of the page it says one decimal place so i do that so its "13.9" type it in and its wrong i tried "13.8" and its wrong aswell can anyone enlighten me?

thanks

BTW it said - Hard luck - remember that the opposite sides of a rectangle are equal.

i did that and still wrong :eusa_wall:eusa_wall:rolleyes:

[sierk1]

The sum of the squares of the two rectangle sides equals the square of the diagonal side.
So in this case 7^2+e^2=12^2 (^2 means squared).
This gives e^2=144-49=95, and you can calculate e by taking the square root.

[Bibliophobia]

woah sierk

but its not hard maths

[PlKEY-ARMY]

oh yes thanks alot sierk was too late mind wasnt working i was adding not subtracting haha

[Janet Snakehole]

Thats just totally confused me up there. LOL.
Im so rubbish at Maths!
I've already had a maths exam, and I think I failed.
Oh noes.
:(

[spot.]

ez ez EASY

[Anarchy]

Ahh maths! :<

[bubble79]

http://www.bbc.co.uk/schools/gcsebitesize/img/ma10032.gif For this third one you would work out the length thats not labelled because the bottom length of the larger triangle is 6 and the hypotenuse is 8 so you can work out that lengtjh by doing 8^2- 6^2 which equals 64-36= 28 and square rooting that leaving 5.2915026221291811810032315072785 which if you then use pythangoras again with the bottom length of 4 then you canwthen work out G which is 27.999999999999999999999999999997+16 and square root that so the fianl answer is 6.6332495807107996982298654733412 which rounds down to 6.6 which is your answer for the third one.

The second one is easy enbough once you've worked out that the two rihgt angled triangles are equal so unless I've gone wrong somewhere no calculating is needed on that at all. Hope that helps and that I've explained enough. lol