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Maths

http://s478.photobucket.com/user/integratedmath/media/Picture16.png.html

As shown in the link, I am trying to answer this question Any help is appreciated!

Reply 1

TenOfThem

Original post by 333obi

http://s478.photobucket.com/user/integratedmath/media/Picture16.png.html

As shown in the link, I am trying to answer this question Any help is appreciated!

Label the 2 lengths that you were given as equal x (I think they were OA and CD)

Then use similar triangles to set up an equation

Reply 2

333obi

Original post by TenOfThem

Label the 2 lengths that you were given as equal x (I think they were OA and CD)

Then use similar triangles to set up an equation

I have labeled OA as x and CD as x and AB as 1m.

When I set up the equation I get:

20+ x / x = x/ 1

When I then cross multiply I get

x^2= 20 + x

x^2 - x - 20= 0

x= 5 x = -4

Would that be right?

Reply 3

TenOfThem

Original post by 333obi

Well done, remember x is a length so must be positive

Reply 4

333obi

Original post by TenOfThem

Well done, remember x is a length so must be positive

Thanks

http://kopps.ism-online.org/files/2010/11/notes-day-5-key-features-of-parabolas-block-f-2.pdf

Could you please help with question 14?

Reply 5

TenOfThem

Original post by 333obi

Could you please help with question 14?

You have done Q14

What is the problem?

Reply 6

333obi

Original post by TenOfThem

You have done Q14

What is the problem?

I havent done question 14 a) b) and c). The bit that says a) explain why triangles ABE and ACD are similar.
:frown:

Reply 7

TenOfThem

Original post by 333obi

I havent done question 14 a) b) and c). The bit that says a) explain why triangles ABE and ACD are similar.
:frown:

The angles are the same hence they are similar

(b) and (c) are done

Reply 8

333obi

Original post by TenOfThem

The angles are the same hence they are similar

(b) and (c) are done

Could you please explain how you got to that answer in question a)

Reply 9

Liamnut

Original post by 333obi

Could you please explain how you got to that answer in question a)

There are three ways of telling a set of triangles are similar, which one you use depends on what infomation you're given

1. All three pairs of corresponding angles are the same.
2. All three pairs of corresponding sides are in the same proportion
3. Two pairs of sides in the same proportion and the included angle equal.

Tenofthem used the first way.