MHB Help Me Find the Perimeter of Tn+1

  • Thread starter Thread starter veronica1999
  • Start date Start date
  • Tags Tags
    Perimeter
Click For Summary
The discussion revolves around calculating the perimeter of a sequence of triangles, starting with T1, which has sides 2011, 2012, and 2013. The sequence is defined such that Tn+1 has side lengths determined by the points of tangency of the incircle of triangle ABC. The perimeter of the final triangle in the sequence is stated to be 1509/28, although there are some calculations leading to different values, including 1509/128. The triangle inequality rule is highlighted as a crucial factor in determining the validity of the triangle's existence in the sequence. Ultimately, the correct perimeter is confirmed to be 1509/128.
veronica1999
Messages
61
Reaction score
0
Could I get some help please?Let T1 be a triangle with sides 2011, 2012, and 2013. For n > = 1, if Tn = triangle ABC
and D, E, and F are the points of tangency of the incircle of triangle ABC to the
sides AB, BC, and AC, respectively, then Tn+1 is a triangle with side lengths
AD, BE, and CF, if it exists. What is the perimeter of the last triangle in the
sequence (Tn) ?

The answer is 1509/28.

Please do not laugh at my solution.

6036/2 , 6036/4 ,6036/8 ... 6036/4096.
I put 4096 as the last term because the next one is 8192

My answer 6036/4098 = 1509/1024
 
Last edited:
Mathematics news on Phys.org
veronica1999 said:
Could I get some help please?Let T1 be a triangle with sides 2011, 2012, and 2013. For n > = 1, if Tn = triangle ABC
and D, E, and F are the points of tangency of the incircle of triangle ABC to the
sides AB, BC, and AC, respectively, then Tn+1 is a triangle with side lengths
AD, BE, and CF, if it exists. What is the perimeter of the last triangle in the
sequence (Tn) ?

The answer is 1509/128.

Please do not laugh at my solution.

6036/2 , 6036/4 ,6036/8 ... 6036/4096.
I put 4096 as the last term because the next one is 8192

My answer 6036/4098 = 1509/1024

The stopping condition is where the longest of \(AD\), \(BE\), \(CF\) for \(T_n\) is greater than the sum of the other two.

So do you know the relationship between the sides of consecutive triangles in the sequence?CB
 
Last edited:
Thanks!

I see I forgot to consider the triangle inequality rule.

6036/512 = 11.787

11.787/3 = 3.92

2.92 3.92 4.926036/1024 = 5.89

5.89/3 = 2.96

0.96 1.96 2.96
 
Last edited:
Oops it was my mistake. I meant 1509/128. Sorry.
 
veronica1999 said:
Oops it was my mistake. I meant 1509/128. Sorry.

Which is what I get.

CB
 
Last edited:

Similar threads

  • · Replies 1 ·
Replies
1
Views
972
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
Replies
2
Views
6K