Year 7 maths help

Original post by bencrossley1

I would hazard a guess that this is simply a typing error in the text book, and I agree with your assumption that it should be 7cm, since all the others(i, ii, iv) have the same length.

Many text books have the odd question in them which has information missing, or is unsolvable, when enough are found, and new edition of the text book is published.

The answer to 7a is 7b1

(edited 12 years ago)

Reply 6

username943595

Well.. That's not a hard question for a year 7, as we get taught this stuff in like year 6..

Reply 7

Azland

8

Feels so strange seeing such questions after so long.

Reply 8

TenOfThem

Original post by steve2005

The answer to 7a is 7b1

And 7biv

Reply 9

Ra Ra Ra

10

I always used to get confused over area and perimeter, and whether or not they were the same thing :h:

I suck at Maths...

Reply 10

dugdugdug

14

It's what's called an ill-posed question.

Maths is about logic and the only way to work out the answer is to assume the width in iii is 7cm.

But it is illogical to have to assume that because the width is GIVEN for i), ii) and iv)

Reply 11

Venomilys

13

ZOMG, an unsolvable GCSE, no wait... not GCSE, pre-GCSE maths question!

God, please... it's too early for judgement day! :adore:

Reply 12

I don't get what is wrong with the question. The clue is surely in the word 'MUST' in the question. Only i and iv MUST have the same perimeter, ii doesn't and iii might. Of course you could be really pedantic and say that none of them 'MUST' have equal perimeters unless you know some or all of the angles, because they could be a fraction of a degree off of what you assume them to be.

(edited 12 years ago)

Reply 13

TenOfThem

Original post by James82

I don't get what is wrong with the question. The clue is surely in the word 'MUST' in the question. Only i and iv MUST have the same perimeter, ii doesn't and iii might. Of course you could be really pedantic and say that none of them 'MUST' have equal perimeters unless you know some or all of the angles, because they could be a fraction of a degree off of what you assume them to be.

That is fine for (a)

but for (b) where the OP has the issue ... how would you find the perimeter of (iii)

Reply 14

Original post by TenOfThem

That is fine for (a)

but for (b) where the OP has the issue ... how would you find the perimeter of (iii)

It's irrelevant, you don't need to find the perimeter of iii to be able answer the question, if you don't have enough information then clearly the perimeter may or may not be the same as a, therefore it doesn't fulfil the criteria that it MUST have the same perimeter as the green rectangle.

Like I said without knowing enough of the angles then none of the shapes in b fulfil the criteria.

Reply 15

RinniieX

who browses through year 7 text books anyway? :confused:

Reply 16

Original post by RinniieX

who browses through year 7 text books anyway? :confused:

Year 7s?

Reply 17

TenOfThem

Original post by James82

It's irrelevant, you don't need to find the perimeter of iii to be able answer the question, if you don't have enough information then clearly the perimeter may or may not be the same as a, therefore it doesn't fulfil the criteria that it MUST have the same perimeter as the green rectangle.

You are still referring to part (a) of the question

The OP is referring to part (b) ... where you do have to find the perimeter because that is what the question asks for!

Reply 18