isolation brain teaser

[sunnybob]

I need more help with my non existent geometry please. :lol: :lol:

Sorry, the marker pen bled into a blur but you get the idea I hope.
if the rear of the shape labelled "A" is 64 cm long,
and the angle A-C is 40 degrees
and both B and D are 10 cm long,

What is the length of C, and E.

Your time starts........NOW.
8) 8) 8)

 

[AES]

3.72491 banannas

 

[marcros]

How accurate does it need to be?

 

[Sheffield Tony]

C = (A - 10cm) / cos(40)
E = (A - 10cm) * tan(40) + 10cm.

C~= 70.5
E ~= 55.3

I think ...

 

[marcros]

I make C 68cm and E 64cm, but let's see if there is a consensus of opinion before you cut anything.

For setting out you will need a triangle with A + the missing bit being 64 + 11.9cm and E + missing bit being 75.9 cm

 

[Fitzroy]

I get the same as SheffieldTony

C. 70.5cm
E. 55.3cm

All maths assumes angle A to E is 90degs.

F.

 

[LeeElms]

(cheating) using CAD. I also agree with Sheffield Tony:

C 70.49
E 55.31

 

[sunnybob]

I'm making a shelf across a corner so accuracy plus or minus a couple mm, but no more.
Aes seems to be on the right track though :roll: :roll: :roll:

I dont have any scrap big enough to make a template, and every time I try to draw a scale on graph paper, it NEVER turns out to be correct, and for this I would need to tape a dozen sheets together.

Lets see if any one else can help, or will phone a friend for me. :roll: :lol:

2 more replies have arrived while typing this, looks like we have a consensus. =D> =D> =D>

 

[marcros]

Ignore mine then.

 

[Fidget]

I drew this out in SketchUp and this is what I got

 

[marcros]

I went completely wrong somewhere and I am still not sure I could get there with the correct answer in front of me!

 

[transatlantic]

I cheated.

 

[AES]

Sorry about that sunnybob. I couldn't resist - today's me birfday, yer see.

MUST be true, it says so down the bottom of the UKW Homepage.

 

[sunnybob]

I would love to be able to do this stuff, but theres an empty drawer in the filing cabinet of my brain labelled "all maths above plus and minus"
Too late to start the OU now though.

Clever, or cheat (which is a form of clever in its own right, dont forget cheating never did captain kirk any harm :shock: )
Thanks to all (except Marcros :roll: )
And if it is Andys burpday, who am I to quibble over a few (thousand) bananas.
(4 weeks till mine, hint hint, nudge nudge, say no more) 8) 8) 8) 8)

I have the ply shelf cut, now to make the walnut edging, which is tricky as the last piece of walnut I have is juuuusssstttt long enough. :roll:

 

[AES]

Ah well Bob, if it's still 4 weeks to yours, at least you're not "a bull in a china shop" like me

Enjoy yer banannas

 

[sunnybob]

We dont believe in astrology :roll: :roll: :roll:

Did you see what I did there? =D> =D> =D> 8) 8)

 

[AES]

Nah, sorry. You'll have to explain that one

 

[sunnybob]

Trouible with irony on a web page, you cant besure if its coming back to you or not.
:roll: :roll:

Me = Gemini = twins= "we" dont believe in twins. =D> =D> =D>

Or, to put it another way; I dont believe in that, oh yes we do. 8) 8) 8)

 

[DrPhill]

A bit like "I don't believe in astrology because I am a Leo and Leos are not gullible"

 

[sunnybob]

You got it.
=D> =D> =D> =D>