SOLUTION: Triangle ABC has AB = 6. Let D lie on BC such that \overline{AD} bisects \angle BAC. If BD = 3 and CD = 5, what is CD?

Algebra ->  Triangles -> SOLUTION: Triangle ABC has AB = 6. Let D lie on BC such that \overline{AD} bisects \angle BAC. If BD = 3 and CD = 5, what is CD?      Log On


   



Question 1210193: Triangle ABC has AB = 6. Let D lie on BC such that \overline{AD} bisects \angle BAC. If BD = 3 and CD = 5, what is CD?
Found 3 solutions by CPhill, ikleyn, greenestamps:
Answer by CPhill(1959) About Me  (Show Source):
You can put this solution on YOUR website!
You've already stated that CD = 5 in the problem. It seems there might be a typo, and you intended to ask for something else, such as the length of AC.
Let's solve for AC, assuming that's what you meant to ask.
**1. Angle Bisector Theorem**
The Angle Bisector Theorem states that if AD bisects angle BAC in triangle ABC, then:
AB/AC = BD/CD
**2. Plug in the Given Values**
* AB = 6
* BD = 3
* CD = 5
6/AC = 3/5
**3. Solve for AC**
* Cross-multiply: 3 * AC = 6 * 5
* 3 * AC = 30
* AC = 30 / 3
* AC = 10
**Therefore, if the question was to find AC, the answer is AC = 10.**
**If you intended to ask another question about CD, please clarify and I'll be happy to help.**

Answer by ikleyn(52747) About Me  (Show Source):
You can put this solution on YOUR website!
.
Triangle ABC has AB = 6. Let D lie on BC such that \overline{AD} bisects \angle BAC.
If BD = 3 and CD = 5, what is CD?
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Hello, in your post, the question is "what is CD ?"

But in the problem's description, CD is given directly and explicitly: "CD =5".

So, your post is, obviously, DEFECTIVE.

It needs to be fixed/repaired/edited, so as not to look too stupid.


An attentive well-wisher, @ikleyn, smiling.



Answer by greenestamps(13195) About Me  (Show Source):
You can put this solution on YOUR website!


Clearly the question that is asked is not the question that was SUPPOSED to be asked, because the length of CD is given.

It is rather obvious, from the kind of information that is given, that the intended question was the length of AC. In that case, the operative principle is that the angle bisector of an angle of a triangle divides the opposite side into two segments whose lengths are in the same ratio as the lengths of the two sides of the triangle that include the given angle.

Then, since the ratio of the lengths of BD and CD is 3:5 and side AB has length 6, side AC has length 10 by a simple proportion:

3%3A5=6%3Ax
3x=30
x=10

ANSWER (to the intended question): 10