For this scalene triangle: which of the following is true?

  • Thread starter Thread starter s3a
  • Start date Start date
  • Tags Tags
    Triangle
Click For Summary

Homework Help Overview

The problem involves a scalene triangle and examines relationships between its sides and angles, as indicated by the original poster's reference to a metric relationships summary. The discussion centers around determining the validity of various statements related to the triangle's properties.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the implications of angle bisection on triangle relationships, question the applicability of certain metric relationships, and consider the conditions under which specific statements about the triangle may hold true.

Discussion Status

The discussion is active, with participants providing insights and suggestions for understanding the relationships in the triangle. There is a focus on the bisected angle and its effects, and some participants have made progress in articulating their reasoning.

Contextual Notes

There is mention of a specific diagram and accompanying documents that may not fully apply due to the geometric configuration of the triangle, particularly regarding perpendicularity and angle relationships.

s3a
Messages
828
Reaction score
8

Homework Statement


The problem is attached as TheProblem.jpg and the answer is D.

Homework Equations


Perhaps the equations attached in Metric relationships summary.pdf.

The Attempt at a Solution


My logic is as follows:
For A, XW does not necessarily equal WZ.

For B, it seems that they are trying to trick the student into thinking of h^2 = d*e (from the Metric relationships summary.pdf file).

For C, the ratio does not work out because the angle facing each respective smaller/larger leg is different.

For D, I can't figure it out but it seems to relate to the Metric relationships summary.pdf file I attached.

Any input would be greatly appreciated!
Thanks in advance!
 

Attachments

  • Metric relationships summary.jpg
    Metric relationships summary.jpg
    41.7 KB · Views: 603
  • TheProblem.jpg
    TheProblem.jpg
    16.9 KB · Views: 589
Physics news on Phys.org
The metric summary table does not quite apply here because the line YW is not perpendicular to XZ.

What it shows you is that the angle at Y has been bisected - so that ∠XYW = ∠WYZ.
The question wants to know if you understand what this does to the relationships.

One way of thinking this through is to figure wat it would take for each condition to be true: what does it mean?

For instance, A is true if the two sub-triangles are similar (since they share a side, this means the overall triangle XYZ must be isosceles.)

Of course, another approach is to physically (and carefully) draw a few (large) scalene triangles, bisect one angle, and then measure the corresponding sides :)
 
Thanks!

Thanks to you telling me to focus on the bisected angle, I basically converted the answer D into words to make sense of it:

(small leg of small triangle)/(hypotenuse of small triangle) = (small leg of large triangle)/(hypotenuse of large triangle).

The "hypotenuse of small triangle" part is technically not the hypotenuse of the small triangle but rather a length that is equivalently large as it.
 
Great, well done.
Putting it in words is a pain - personally I relabel these things with lower case for side lengths and upper case for the corresponding angles.
 

Similar threads

Replies
2
Views
3K
Replies
8
Views
6K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 6 ·
Replies
6
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 10 ·
Replies
10
Views
4K