Wikipedia:Reference desk/Archives/Mathematics/2012 August 18

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August 18

Equilateral triangle

Can we take out the [proof of] radius of the circumscribed and incircle of an equilateral triangle without using trig? extra999 (talk) 07:29, 18 August 2012 (UTC)

Well, you can find the inradius and the circumradius using only the Pythagorean theorem, so depends whether you count that as "trig". First step is to show that the inradius is half of the circumradius. Gandalf61 (talk) 07:57, 18 August 2012 (UTC)

How can we show that the inradius is half of the circumradius? extra999 (talk) 08:43, 18 August 2012 (UTC)

The incircle and circumcircle have the same centre - label this O. Label one vertex of the triangle A and the midpoint of an adjacent side B. Draw triangle OAB. OA is the circumradius of the triangle and OB is its inradius. Find the angles OAB and AOB and show that triangle OAB is half of an equilateral triangle. Gandalf61 (talk) 11:21, 18 August 2012 (UTC)

Got it thanks, extra999 (talk) 12:49, 18 August 2012 (UTC)

Algorithum for fights

Would it be possible to locate a program or software or algorithum that would be able to use math to find out who would win in a fight? — Preceding unsigned comment added by 205.142.178.36 (talk) 17:45, 18 August 2012 (UTC)

If you mean calculating the odds for a boxing match based on the records of each opponent, then, yes, that should be possible. Is that what you meant ? StuRat (talk) 18:16, 18 August 2012 (UTC)

can you add in your own variables and such for fictinal fighting so i can settle scores on who would win in a fight. also where can i get such a program? — Preceding unsigned comment added by 205.142.178.36 (talk) 19:04, 18 August 2012 (UTC)

Do you mean questions like "Who would win in a fight between a Cylon and a Dalek?"? If so, those questions are meaningless and cannot be answered mathematically. --Tango (talk) 20:33, 18 August 2012 (UTC)

It is possible they do it on deadlyest worrior — Preceding unsigned comment added by 205.142.178.36 (talk) 20:54, 18 August 2012 (UTC)

Have you read Deadliest Warrior? hydnjo (talk) 21:49, 18 August 2012 (UTC)

Keep in mind that that is an entertainment show. It is intended to be entertaining, not accurate. --Tango (talk) 01:53, 19 August 2012 (UTC)

See Lanchester's_laws. Bo Jacoby (talk) 12:15, 19 August 2012 (UTC).