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Topic: two-column proof
Replies: 4   Last Post: Nov 11, 1998 3:13 PM

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 Walter Whiteley Posts: 146 Registered: 12/3/04
Re: two-column proof
Posted: Nov 11, 1998 3:13 PM

I take 'congruent to MEAN that there is an isometry
(a transformation preserving distances) which places one object
to coincide with the other.

Then, if whatever you want to measure (angle area, etc.) is
unchanges by such transformations, the two objects give
the same measurements.

Walter Whiteley
York University
>
> In article <3648DB75.6BF6@world.std.com>, pash@world.std.com says...

> > Just step back and think about that. If two triangles are congruent,
> > that means they have the same shape. In fact, you must have proved a
> > theorem which says that if two triangles are congruent (or even
> > similar), then their corresponding angles are equal. And isn't that what
> > you are trying to prove?
> >

>
> I think I get what you are saying. The next step would be to prove
> that the triangles are congruent. From their you can establish that
> Angle PTR corresponds to Angle QTR. If this is correct then I'm at a
> lost to find a suitable theorem or postulate for this.
>
>

Date Subject Author
11/10/98 TiGER
11/10/98 Peter Ash
11/11/98 TiGER
11/11/98 TiGER
11/11/98 Walter Whiteley