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## #1 2012-09-08 19:03:01

Agnishom
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### A few simple proofs about Triangles

Let there be a triangle ABC and O a point inside it.
Now, how can I prove that:
1.

2.

Last edited by Agnishom (2012-09-08 19:04:17)

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'The whole person changes, why can't a habit?' -Alokananda

## #2 2012-09-08 20:59:19

bob bundy
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### Re: A few simple proofs about Triangles

hi Agnishom

Here's a start for number 2.

AO + OB > AB

Bob

You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

## #3 2012-09-08 22:15:42

Agnishom
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### Re: A few simple proofs about Triangles

I did 2.

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'The whole person changes, why can't a habit?' -Alokananda

## #4 2012-09-08 22:28:22

bob bundy
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### Re: A few simple proofs about Triangles

Excellent!

I am hoping there's a similar way to do Q1 but, so far, it has eluded me.

Bob

You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

## #5 2012-09-08 22:37:29

Agnishom
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### Re: A few simple proofs about Triangles

I remember doing it at the 7th Grade, but what about 1.?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'The whole person changes, why can't a habit?' -Alokananda

## #6 2012-09-08 23:27:25

noemi
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### Re: A few simple proofs about Triangles

Hint for 1.:
OA+OB<CA+CB

Last edited by noemi (2012-09-08 23:29:34)

## #7 2012-09-09 01:55:11

Agnishom
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### Re: A few simple proofs about Triangles

#### noemi wrote:

Hint for 1.:
OA+OB<CA+CB

Why?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'The whole person changes, why can't a habit?' -Alokananda

## #8 2012-09-09 01:56:12

Agnishom
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### Re: A few simple proofs about Triangles

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'The whole person changes, why can't a habit?' -Alokananda

## #9 2012-09-09 02:23:50

noemi
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### Re: A few simple proofs about Triangles

OA+OB<CA+CB
OB+OC<AB+AC
OC+OA<BC+BA

adding all those you get what you need, assuming CA=AC etc.

## #10 2012-09-09 11:59:03

Agnishom
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### Re: A few simple proofs about Triangles

Hmmmmmm..................
That set of problem had another problem which I shall be posting in a new thread

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'The whole person changes, why can't a habit?' -Alokananda