Year 12s: what will be the first way you research your future options? >>

serious help needed

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Here you are: :smile:

OK. You've assumed that CE is a diameter - it's not.

You need to work out the distance of the line DE from the centre to start. Since you now know the radius, and the length of DE, ....

Reply 21

User23

Original post by ghostwalker

OK. You've assumed that CE is a diameter - it's not.

You need to work out the distance of the line DE from the centre to start. Since you now know the radius, and the length of DE, ....

yeah but is it not asking for the radius?

Reply 22

ghostwalker

Original post by User23

yeah but is it not asking for the radius?

You've already got the radius.

You were talking about AB in your most recent posts, and that's what I replied to.

Reply 23

User23

Original post by ghostwalker

You've already got the radius.

You were talking about AB in your most recent posts, and that's what I replied to.

Oh yes course, ok so if r=25cm.. i really dont know what to do from here haha

Reply 24

ghostwalker

Original post by User23

Oh yes course, ok so if r=25cm.. i really dont know what to do from here haha

Same as you're already been doing. Pythagoras to find the distance to the line DE.

Reply 25

User23

Original post by ghostwalker

Same as you're already been doing. Pythagoras to find the distance to the line DE.

wait a minute i assumed that the diameter was CE so i think i got 25 as the radius for the wrong reasons

Reply 26

ghostwalker

Original post by User23

wait a minute i assumed that the diameter was CE so i think i got 25 as the radius for the wrong reasons

Your derivation of the radius doesn't depend on CE being a diameter, only that OC is a radius, as is OE.

Reply 27

User23

Original post by ghostwalker

Your derivation of the radius doesn't depend on CE being a diameter, only that OC is a radius, as is OE.

Oh right ok, so the radius does not link with the diameter then

Reply 28

ghostwalker

Original post by User23

Oh right ok, so the radius does not link with the diameter then

I presume you've finished this now then: If not post working and/or precisely where you're stuck.

Reply 29

User23

Original post by ghostwalker

I presume you've finished this now then: If not post working and/or precisely where you're stuck.

Yeah i get it now, thank you :smile:

Reply 30

PrimeEpoch

Original post by User23

Here you are: :smile:

I'm trying to do this lol, but I'm fairly sure you can't assume that the midpoint of your hypotenuse is the centre of your circle. Think about what would happen if your AD value changed.

Reply 31

Student403

Original post by PrimeEpoch

I'm trying to do this lol, but I'm fairly sure you can't assume that the midpoint of your hypotenuse is the centre of your circle. Think about what would happen if your AD value changed.