Help I am totally lost. I have to do a proof problem with the statement and reason and I just don't get it.

Given: DB bisects /ADC

AD congruent CD

Prove: DB ' AC

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- Dec 2nd 2013, 04:58 AMFentonjcDb bisects adc help!!
Help I am totally lost. I have to do a proof problem with the statement and reason and I just don't get it.

Given: DB bisects /ADC

AD congruent CD

Prove: DB ' AC - Dec 2nd 2013, 05:26 AMMelody2Re: Db bisects adc help!!
- Dec 2nd 2013, 05:55 AMMelody2Re: Db bisects adc help!!
Hi Fentonjc,

I am going to assume that /ADC means angle ADC

and DB ' AC means DB bisects AC (the only other alternative that I can think of is that DB is perpendicular to AC and the proof would be similar)

Draw the picture first of course

Let X be the intersection of DB and AC

Consider triangle ADX and triangle CDX

you can prove that these 2 triangles are congruent and hence show that AX=CX

then give a concluding statement and you are finished.

Is that enough help?

Melody. - Dec 2nd 2013, 08:00 AMSorobanRe: Db bisects adc help!!
Hello, Fentonjc!

I am getting better at Mathematical Forensics.

II understand the problem . . .*think*

Quote:

. . . . . .

. . . . . .

Code:`D`

*

/|\

/ | \

/ | \

/ | \

/ | \

/ | \

/ | \

A * - - - * - - - * C

B

We are told that bisects

Then: .

Also: . (Identity)

So: . (s.a.s.)

Hence: . (corresponding parts)

We see: .

Since

Therefore: .

- Dec 2nd 2013, 06:09 PMFentonjcRe: Db bisects adc help!!
I tried to attach the actual picture. Then it has a box that has 2 sides ones says statements and the other says reasons.

it is a triangle that has a D on top and A B C on the bottom and it also has a 1 and 2 inside the triangle under the D - Dec 2nd 2013, 07:17 PMMelody2Re: Db bisects adc help!!
There you go Soroban. You are good at Forensic mathematics! You even had the diagram around the right way.

I'm impressed.

I have a soroban. It was given to me by a Japanese exchange student. It was a great gift!