Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
Drexel University or The Math Forum.
|
|
|
|
Re: similar triangles
Posted:
Aug 1, 1996 5:46 PM
|
|
Tim Doskoch wrote:
>
> We know that if two angles of one triangle are equal to two angles of
> another triangle, then the triangles are similar, and corresponding sides
> have the same ratio.
>
> So if we have two triangles ABC and DEF (labeled clockwise from the apex),
> where angle A = angle D and angle B = angle E then: AB/DE = BC/EF = CA/FD.
>
> Often, somebody will use AB/BC = DE/EF and get the same answer as if they
> used the above ratios.
>
> In what circumstances can you mix up the similar ratios with a correct result?
>
> This also begs the question, in what circumstances will you not get a
> correct result?
>
> Tim Doskoch
> Edmonton, Alberta
> Canada
Since we may assume BC and EF <> 0, I guess I see the two statements:
AB/DE = BC/EF and AB/BC = DE/EF
as equivalent!
AB/DE = BC/EF --> AB*EF = DE*BC --> AB*EF/BC=DE --> AB/BC = DE/EF
--
Howard L. Hansen
Assistant Professor of Mathematics
Western Illinois University
Macomb, IL 61455
http://www.ECNet.Net/users/mfhlh/wiu/index.htm
"Good mathematics is not how many answers you know,
but how you behave when you don't know the answer."
|
|
|
|
