Trigonometry Triangle Help: Finding Unknown Angles and Sides

AI Thread Summary
To find the unknown angle (feta) in a right triangle with a hypotenuse of 10m and an opposite side of 4m, the sine function should be used, defined as the ratio of the opposite side to the hypotenuse. The correct calculation is sin-1(4/10) to determine feta. For the second question regarding the height of a plane, the height can be calculated using the sine function as well, specifically 2000 x sin(50 degrees). Understanding the definitions of sine and cosine is crucial for solving these types of trigonometric problems. Proper application of these concepts will lead to accurate solutions.
blueparukia
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First off, I was just moved up a grade (about 2 week ago) and the class is studying trigonometry.


Homework Statement


I have a triangle:
Hyp = 10m
Opp = 4m
Adj= Unknown
Feta = Unknown

And I need to find feta.

Homework Equations


?


The Attempt at a Solution


Well, I have tried a lot of random things lol.
E.g: sin-1 (10x4)

Well, that's actually about it.


I also have another question. Exactly from the revision sheet.
By using a radar beam. an observer at A determinses that a plane at B is 2000 metres away (AB=2000) Use the information given to calculate the height of the plane above the horizontal \overline AC The angle is 50 degrees. I know the answer is 2000xsin 50, but how do I know t is sin? The teacher gave me the answer, but I don't know how she came up with sin :(


Please help,

BP
 
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In order to do that, you first need to know the definitions of sine, cosine, etc!

sine is defined, in a triangle,as "opposite/hypotenuse", NOT "opposite times hypotenuse. You need to find sin-1(4/10).
 
4/10 thank you! I was using 4x10. Completely forgot.

Thankl you,

BP
 

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