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# Once again, it's mee watch

1. Hi maths experts, Ok so i came across this question and I came up with an answer, idk if it's correct. i got 150.2587..
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2. (Original post by User23)
Hi maths experts, Ok so i came across this question and I came up with an answer, idk if it's correct. i got 150.2587..
Would you like to show some working so that we can see where you went wrong?
3. (Original post by User23)
Hi maths experts, Ok so i came across this question and I came up with an answer, idk if it's correct. i got 150.2587..
I got something near the high 90s around 97.something - but I did that without pen & paper.
4. (Original post by User23)
Hi maths experts, Ok so i came across this question and I came up with an answer, idk if it's correct. i got 150.2587..
I got a different answer. I'm not supposed to give full answers so I'll try to guide you.

What do you think the first step is? Talk us through the working and we'll see where you went wrong.
5. (Original post by nucdev)
I got something near the high 90s around 97.something - but I did that without pen & paper.
Same.
6. (Original post by BuryMathsTutor)
Would you like to show some working so that we can see where you went wrong?
Oh damn it's wrong?! Ok, so this was my working out:
So since the area of the square is 84.5cm^2 i square rooted this to get the sides and this gave me 9.1923.. then i assumed that the height of the trapezium is 9.1923 and to find out the longer length of the trapezium i did 11.75+9.1923..= 20.9423 then i used 1/2(a+b)h so, 1/2(11.75+20.9423)9.1923 which gave me 150.2587
7. (Original post by nucdev)
I got something near the high 90s around 97.something - but I did that without pen & paper.
HOW?
8. Ok i got it i got it!!
9. (Original post by hydeman)
same.
i got 97.4981!!!
10. (Original post by User23)
i got 97.4981!!!
Excellent - around about what I got.
11. (Original post by User23)
i got 97.4981!!!
Nice one! Did you you round the awkward number you get by square rooting 84.5? It later gives a clean 1 d.p. number when you use trigonometry and the final answer I got was exactly 97.5 cm2 although yours is so close that I don't think any examiner would care.

Edit: Out of interest, what level is this? Is it GCSE, A Level, or one of the Scottish/Irish equivalents of those?
12. (Original post by Hydeman)
Nice one! Did you you round the awkward number you get by square rooting 84.5? It later gives a clean 1 d.p. number when you use trigonometry and the final answer I got was exactly 97.5 cm2 although yours is so close that I don't think any examiner would care.
Yeah that's probably what she did - I did that as well only because I had a basic calculator and no pen & paper and got a long decimal.
13. (Original post by Hydeman)
Nice one! Did you you round the awkward number you get by square rooting 84.5? It later gives a clean 1 d.p. number when you use trigonometry and the final answer I got was exactly 97.5 cm2 although yours is so close that I don't think any examiner would care.

Edit: Out of interest, what level is this? Is it GCSE, A Level, or one of the Scottish/Irish equivalents of those?
This is from the 2014 Maths II Westminster 13+ scholarship entry paper.

You can find them here: https://www.westminster.org.uk/admis...hips-bursaries (scroll to the bottom)
14. (Original post by User23)
Oh damn it's wrong?! Ok, so this was my working out:
So since the area of the square is 84.5cm^2 i square rooted this to get the sides and this gave me 9.1923.. then i assumed that the height of the trapezium is 9.1923 and to find out the longer length of the trapezium i did 11.75+9.1923..= 20.9423 then i used 1/2(a+b)h so, 1/2(11.75+20.9423)9.1923 which gave me 150.2587
This was your mistake I think. That length is of the hypotenuse of the triangle, not of the other sides. So a little trigonometry is in order. Or Pythagoras.

I also got about 97.5 cm^2.
15. (Original post by User23)
Hi maths experts, Ok so i came across this question and I came up with an answer, idk if it's correct. i got 150.2587..

I know you've already figured it out, but here's my solution anyway
16. (Original post by boojiebaba)
This is from the 2014 Maths II Westminster 13+ scholarship entry paper.

You can find them here: https://www.westminster.org.uk/admis...hips-bursaries (scroll to the bottom)
Ah, alright. So it's roughly GCSE-level. I've already finished school so not much good for me, I'm afraid.
17. I was late again
18. (Original post by Imperion)
I was late again

Whenever I'm on a study help thread, there's always that pressure to solve it as quickly as possible so I don't end up having to delete my answer because five other people have already explained it.
19. (Original post by Hydeman)

Whenever I'm on a study help thread, there's always that pressure to solve it as quickly as possible so I don't end up having to delete my answer because five other people have already explained it.
The one time I was early the OP didn't word the title correctly. -_-
20. I also have the consensus answer. Just be sure not to confuse the height of a trapezium (in this case, equivalent to length XY) with the the side equivalent to length AD.

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