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Topic: Need help writing an entire two-column proof
Replies: 4   Last Post: Nov 12, 1998 11:13 AM

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Peter Ash

Posts: 13
Registered: 12/6/04
Re: Need help writing an entire two-column proof
Posted: Nov 12, 1998 7:35 AM
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You left something out of your given. The hypothesis of the theorem
contains the word "altitude". An altitude is not just any old line from
one vertex to a point on the opposite side. What does the fact that AC
is an altitude say about the relationship between AC and BD?

A hint for the proof: Another way of saying "AC bisects the angle BAD"
is "angle BAC = angle CAD".

By the way, the kinds of questions you are asking are things you should
be able to ask your teacher, I think.


TiGER wrote:
> I have a statement and have to write down what the Given is, what To
> Prove, Anaylsis, and Draw a figure, and the two-column proof. Not sure
> how to draw the figure as accurate as possible though. Anyway, here is
> the problem:
> Theorem: In an isosceles triangle, an altitude drawn to the base of
> the triangle bisects the vertex angle of the triangle.
> I drew an isosceles triangle with a line straight down the middle. I
> labeled the points A-D going from left to right and top to bottom.
> This is what I get out of the statement:
> Given: Triangle ABD is an isosceles triangle
> To Prove: Segment AC bisects Angle BAD
> I doubt that is right but that's what I get from the statement.

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