Simple Geom problem.

[Xyzzy]

How did the Babylonians (or whoever) represent their 60 digits?

We're assuming this is not a rhetorical question:

http://en.wikipedia.org/wiki/Babylonian_number_system

[S485122]

Originally Posted by davieddy

How did the Babylonians (or whoever) represent their 60 digits?

They used a mixture of base 10 and base 60, alternating both :
1, 10, 60, 600 (10*60), 3 600 (60*60), 36 000 (10*60*60)...
A symbol for the units, another symbol for ten, another for 60, superposition of the previous two for 600, another for 3 600, superposition of the symbol ten and 3 6000 for 36 000...

For instance u representig the unit, t the ten , s the sixty, r the 600, and o the 3 600, p the 36 000 : pppp ooooo rrrrr ss ttttt u would be 36000+36000+36000+36000+3600+3600+3600+3600+3600+600+600+600+600+60+60+10+10+10+10+10+1=164571
The symbols where grouped in paterns to facilitate reading.
(source Histoire universelle des chiffres by George Ifrah, editor Seghers 1981)

Xyzzy was quicker to answer :-)

[davieddy]

Originally Posted by Xyzzy

We're assuming this is not a rhetorical question:

http://en.wikipedia.org/wiki/Babylonian_number_system

It wasn't. Remembering ~26 letters of the alphabet seems
to be a sensible limit.
BTW was that the royal "we"?

David

[cheesehead]

Originally Posted by davieddy

BTW was that the royal "we"?

No. Xyzzy uses the editorial we (he being head honcho hereabouts), or perhaps a generic third person (See the "Atypical uses of we" section at http://en.wikipedia.org/wiki/We), or pluralis modestiae (rather than pluralis majestatis, the royal we).

OTOH, Xyzzy does have a tendency to do things like inserting false quotations (e.g. "I quote more ... all day!") between one's nym and avatar in the left margin, which seem more imperial than editorial.

[davieddy]

Originally Posted by cheesehead

OTOH, Xyzzy does have a tendency to do things like inserting false quotations (e.g. "I quote more ... all day!") between one's nym and avatar in the left margin, which seem more imperial than editorial.

Speaking of which, what does mine mean?

[Xyzzy]

Speaking of which, what does mine mean?

[Xyzzy]

BTW, for the record, the actions that we take (Xyzzy, and his evil twin Yzzyx) are, for the most part, random, malicious and devoid of meaning.

Some misguided souls have hypothesized that there is a relationship between various psychotropic medications and our behavior but we dismiss that line of thought as a desperate attempt to make something utterly pathetic and unfathomable into something sensible. Sometimes things really stink, no matter how much perfume you put on them.

[cheesehead]

Originally Posted by cheesehead

Xyzzy uses the editorial we (he being head honcho hereabouts), or perhaps a generic third person (See the "Atypical uses of we" section at http://en.wikipedia.org/wiki/We), or pluralis modestiae (rather than pluralis majestatis, the royal we).

Originally Posted by Xyzzy

BTW, for the record, the actions that we take (Xyzzy, and his evil twin Yzzyx)

Well, now that "Yzzyx" is on record, I wish to amend my previous statement.

Xyzzy's earlier use of the editorial we has now progressed into the delusional we. That is, his use has progressed; Xyzzy himself is not actually delusional, but seems desirous of presenting that facade.

[mfgoode]

Originally Posted by davieddy

Speaking of which, what does mine mean?

Its Irish for "a thousand welcomes"

I thought you would get it in my previous post to you when thats how I signed off but you were too busy with my verbosity.

Mally

[davieddy]

Originally Posted by mfgoode

Here is a simple problem from the Maths Tripos.

ABC is an isoceles triangle, whose vertex angle at A is 20* . The point D is on AC such that DBC is 60*. E is on AB such that ECB =50. Find BDE

Mally

Three years ago, this puzzle was entertaining philmoore and me.
I have revisited it and come up with this solution:

Let F be the reflection of B in AC and
let G be the reflection of C in AF.
AD=DB and AGB is equilateral
Let DG intersect AF at H
DGF is 50 degrees so AH=AE

BDE=FDG=30

David

.

[davieddy]

(Myself included)

A picture must be worth at least 50 words

David

PS Or the other way round
(as the actress said to the bishop)