# proof ques

• Feb 16th 2011, 06:23 AM
shubham
proof ques
In a triangle ABC, D,E & F are any 3 points on sides AB,BC & CA
respectively..given that
we need to prove that ABC is equilateral. ny help??
• Feb 17th 2011, 04:15 PM
Sudharaka
Quote:

Originally Posted by shubham
In a triangle ABC, D,E & F are any 3 points on sides AB,BC & CA
respectively..given that
we need to prove that ABC is equilateral. ny help??

Draw a figure with the given details and you will be able to see that the traingles ABC and ADF are similar. Also the traingles ABC and BDE are similar. So for each pair the corresponding sides will have the same ratio. From these relationships you can get a proportionality of sides in traingles ADF and BDE. Hence you can say that ADF and BDE are similar. Hope you can continue.
• Feb 17th 2011, 09:49 PM
shubham
how can you say ABC and ADF are similar,,dear,,it is not given that DF//BC ...(Wondering)
• Feb 17th 2011, 09:50 PM
shubham
nor any such condition is given where you can prove ADF similar to ABC..
• Feb 17th 2011, 10:24 PM
Sudharaka
Quote:

Originally Posted by shubham
nor any such condition is given where you can prove ADF similar to ABC..

I have taken ADF=BED=ECF instead of ADF=BED=EFC. It was now that I saw the error I had done. Sorry for the mistake. I havent come up with a answer for the original post yet.
• Feb 18th 2011, 05:11 AM
shubham
ohhk..