Finding the lengths of the sides using a given angle

  • Thread starter greggory
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In summary: So, using the "law of sine", the side length would be:sin(38.831178435) = 0.785398161...In summary, this problem is impossible.
  • #1
greggory
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Homework Statement


Well, here is the problem. Assuming that the shape is a triangle, find the lengths of all sides, given one angle is 51.168821565 degrees using the law of sine.

sin(51.168821565) = 0.785398161...

The Attempt at a Solution


I basically tried using the theorems, such as that all angles will add up to 180 degrees and A+B > C always.

I tried to find the lengths, but couldn't. Help would be appreciated.

EDIT:

I tried this:
d = opposite
h = hypotnues
sin 51.168821565 = d / h
d / h = 0.785398161

Does this mean there are infinite numbers that can fit side lengths?
 
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  • #2
There are infinitely many triangles with only one angle given.
 
Last edited:
  • #3
greggory said:

Homework Statement


Well, here is the problem. Assuming that the shape is a triangle, find the lengths of all sides, given one angle is 51.168821565 degrees using the law of sine.
This is impossible. As th4450 said, there are an infinite number of different triangles having that angle. Draw the angle choose any point on one ray, any point on the other and connect them.n Go back and reread the problem. You have to be given at least one side.

sin(51.168821565) = 0.785398161...


The Attempt at a Solution


I basically tried using the theorems, such as that all angles will add up to 180 degrees and A+B > C always.

I tried to find the lengths, but couldn't. Help would be appreciated.

EDIT:

I tried this:
d = opposite
h = hypotnues
sin 51.168821565 = d / h
d / h = 0.785398161

Does this mean there are infinite numbers that can fit side lengths?
That formula works only for right triangles. You say that you are to use the "law of sine". Do you know what that is? (Not the definition of sine.) In order to use the "law of sine" to find the length of a side, you must already know two angles and one side.
 
  • #4
Well, I accidently left out some information. The other angle is 90 degrees, which means that the other angle must be 38.831178435, right? Also, one given side is 25(if I read the problem right this time).
 

What is the formula for finding the length of a side using a given angle?

The formula for finding the length of a side using a given angle is side length = opposite side length / sine of the given angle.

Can I use any angle to find the length of a side?

Yes, as long as you know the length of the opposite side, you can use any angle to find the length of a side using the formula side length = opposite side length / sine of the given angle.

What if I don't know the length of the opposite side?

If you don't know the length of the opposite side, you will not be able to find the length of the side using a given angle. You will need to know at least two sides and one angle to find the length of a side using trigonometric functions.

Is it possible to find the length of a side using a given angle without using trigonometric functions?

No, trigonometric functions, such as sine, cosine, and tangent, are specifically designed to find the relationships between sides and angles in a right triangle. Without using trigonometric functions, it would be difficult to find the length of a side using a given angle.

Can I use this formula for non-right triangles?

No, this formula is specifically for finding the length of a side in a right triangle. For non-right triangles, you will need to use other methods, such as the Law of Sines and Law of Cosines, to find the length of a side using a given angle.

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