How Do Theta, Opposite Side, and Hypotenuse Relate in Trigonometry?

  • Context: High School 
  • Thread starter Thread starter awholenumber
  • Start date Start date
  • Tags Tags
    Trigonometry
Click For Summary

Discussion Overview

The discussion revolves around the relationships between the angle theta, the opposite side, and the hypotenuse in the context of trigonometry, specifically focusing on the sine function and the concept of ratios in right-angled triangles. Participants explore definitions and implications of these relationships, as well as their understanding of the terms involved.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants assert that for a given angle theta, the ratio of the opposite side to the hypotenuse remains constant regardless of the triangle's size, defining this relationship as the sine function.
  • Others question the implications of changing the angle, suggesting that the ratio changes with the angle, leading to confusion about the constancy of the ratio.
  • One participant expresses uncertainty about the meaning of "propagation of values" in relation to the ratio of side lengths.
  • Definitions of sine, cosine, and tangent are provided, indicating their relationships to the sides of a right-angled triangle.
  • There is a request for clarification on the term "ratio" and its application in the context of triangles, indicating a desire for foundational understanding.
  • A specific example is given using a 3/4/5 triangle to illustrate the ratio of the opposite side to the hypotenuse.

Areas of Agreement / Disagreement

Participants exhibit some agreement on the definitions of sine, cosine, and tangent, but there is disagreement regarding the effects of changing the angle on the side lengths and ratios, leading to unresolved questions about the constancy of these relationships.

Contextual Notes

There are limitations in the discussion regarding the clarity of terms like "ratio" and "propagation of values," as well as the assumptions about the constancy of ratios when angles change, which remain unresolved.

awholenumber
Messages
200
Reaction score
10
c0060c52d3.jpg


(the x , after the sin is the representation of angle in theta) and it also means ( opposite side length/ hypotenuse side length )

how are these things related ? i mean the angle in theta , the opposite side length / hypotenuse side length ... ??
 
Mathematics news on Phys.org
For a given angle theta, the ratio of those two sides is always the same, no matter how large the triangle is. The relation between the two is the sine function by definition.
 
thanks ,

if you take a sin x , which is sin theta ... it means ... opposite side length / hypotenuse side length ...

the change in the angle is basically going to have no effects at all on the length of the sides of the right angled triangle ... right ?

also at the same time the ratio simply means ,opposite side length / hypotenuse side length ... right ?

for example ,

if you take sin x , and you are given the measurement of the sides of the right angled triangle ...

it again simply means , sin x is opposite side length / hypotenuse side length ...my problem was , i have always seen this like some sort of propagation of values ...

i still don't know why i see this ratio , opposite side length / hypotenuse side length like some sort of value that propagates ...

it is simply a constant value , or ratio of the outer lengths of the right angled triangle depending on the sine , cosine or tan function ??

which is also the ,

sin x , opposite side length/ hypotenuse side length
cos x , adjacent side length / hypotenuse side length
tan x , opposite side length / adjacent side length??
 
Last edited by a moderator:
rosekidcute said:
the change in the angle is basically going to have no effects at all on the length of the sides of the right angled triangle ... right ?
Which change? If you change the angle, the ratio changes as well.
rosekidcute said:
also at the same time the ratio simply means ,opposite side length / hypotenuse side length ... right ?
Yes, that's the ratio we are talking about.
rosekidcute said:
i have always seen this like some sort of propagation of values
What does that mean?
rosekidcute said:
it is simply a constant value , or ratio of the outer lengths of the right angled triangle depending on the sine , cosine or tan function ??
I don't understand that question.
rosekidcute said:
sin x , opposite side length/ hypotenuse side length
cos x , adjacent side length / hypotenuse side length
tan x , opposite side length / adjacent side length
That is the definition of the functions sine, cosine and tangent. Well, one of many possible equivalent definitions.[/size]

Do you understand what a function is?
 
thanks for the answers ... i have few more questions ...

i am really trying to understand a few things from the basics ...

i don't really understand what the word ratio , means in a triangle ...are we trying to find the length of that line passing between the

sin x , opposite side length/ hypotenuse side length
cos x , adjacent side length / hypotenuse side length
tan x , opposite side length / adjacent side length

?
 
Last edited by a moderator:
I don't understand your question.

Consider the angle at the lower left in the 3/4/5 triangle (right side of your picture). The length of the opposite side is 4, the length of the hypotenuse is 5. The ratio of side lengths is 4/5=0.8.
 
thanks for making that part clear ... i was confused a lot about that particular part ...

i even had to look up the definitions of the word ratio itself ...

In mathematics, a ratio is a relationship between two numbers indicating how many times the first number contains the second
 
Last edited by a moderator:

Similar threads

  • · Replies 38 ·
2
Replies
38
Views
6K
Replies
2
Views
1K
Replies
2
Views
2K
  • · Replies 17 ·
Replies
17
Views
11K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K