Math Is Fun Forum

Humphrey

Member

Registered: 2007-05-22

Posts: 2

I need help!!!

Hello everybody. Two days ago I my maths teacher gave me time until tomorrow morning to solve the following exercise:

1. Show that in every triangle there is:

cos A  +  cos B  +  cos C  <  1
a(b+c)    b(c+a)    c(a+b)    8Rr

But most importantly explain in a few words how you managed to solve it, please
Thank you in advance!

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: I need help!!!

What are R and r?

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Why did the vector cross the road?
It wanted to be normal.

mikau

Member

Registered: 2005-08-22

Posts: 1,504

Re: I need help!!!

I see something in there that looks like the law of sines.

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A logarithm is just a misspelled algorithm.

Stanley_Marsh

Member

Registered: 2006-12-13

Posts: 345

Re: I need help!!!

Give u a tip .

R , r are the radius of two circles , scribing the triangle. one is outside , one is inside , I dont know what those are called in English.

Last edited by Stanley_Marsh (2007-05-22 14:36:41)

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Numbers are the essence of the Universe

Humphrey

Member

Registered: 2007-05-22

Posts: 2

Re: I need help!!!

well I thought R and r are international symbols, but anyway I still have time left till monday to do this assignment, so please help!