SOLUTION: *I don't know how to add pictures on here, if anyone could help that'd be great!* So I have a triangle (△PQR) and it's perimeter is 40. In △PQR, there is an angle

Algebra.Com
Question 1117342: *I don't know how to add pictures on here, if anyone could help that'd be great!*
So I have a triangle (△PQR) and it's perimeter is 40.
In △PQR, there is an angle bisector (PL).
Given: Perimeter of △PQR = 40; LR = 15; LQ = 9
FIND PQ
The answer is 6.
My problem is I don't know how to get the answer 6. I do know you have to do a proportion but from all the numbers I've tried, haven't been able to get 6.

Answer by ikleyn(52855)   (Show Source): You can put this solution on YOUR website!
.
Use the theorem:


    In any triangle, the angle bisector divides the side to which it is drawn, in two segments proportional to the ratio of two other sides of a triangle


    (See the lesson On what segments the angle bisector divides the side of a triangle  in this site).



So, |PR| = 15x,  |PQ| = 9x,  where x is an unknown common measure of the segments PR  and  PQ.


Thus for the perimeter you have

15x + 9x + (15+9) = 40  ====>

24x = 40 - (15+9) = 16  ====>  x =  = .


Then  |RL| = 15x =  = 10   and  |PQ| = 9x =  = 6.


Answer.  |PQ| = 6.

Solved.

The key to the solution is the theorem referred above.


RELATED QUESTIONS

Hello, My question is about congruent triangles. I don't know if it is possible to... (answered by ankor@dixie-net.com,math_helper)
I know this question has appeared before on here and it's kind of been semi-answered but... (answered by Theo)
I am having a lot of trouble with word problem questions. If someone could help me that... (answered by Edwin McCravy)
Problem #61 on p. 150 Chapter 2.1 reads - 2/3 - (- 5/8). We've done these before so I... (answered by tutorcecilia)
Hi, I need help solving three questions. They're given as homework and I really don't... (answered by josgarithmetic)
My problem is regarding "demand equation" or demand curve. Here is the word problem:... (answered by MRperkins,solver91311)
Which of the following could be the perimeters of the three squares below? A.12 ft, 16,... (answered by math_tutor2020)
I think my problem with these kinds of questions is that I’m having a hard time... (answered by jsmallt9)
Hi, I'm new here and hope this is the right topic for my question(s)... I have some... (answered by ankor@dixie-net.com)