<p>If you know the distance of each star from earth, and the angle between the stars, then you can us the cosine rule to find their distance from each other.  See this for detail
<a href="https://en.wikipedia.org/wiki/Law_of_cosines" rel="nofollow">https://en.wikipedia.org/wiki/Law_of_cosines</a></p>

CC BY-SA 3.0
2016-08-25T15:02:08.670Z
2016-08-25T15:02:08.670Z
Dr Chuck
<p>For example: I want to know the distance between Alpha Orionis (Betelgeuse) and Beta Orionis (Rigel). Is this possible? You only know the distance from Earth. May be this is a math problem and not an Astronomy question.</p>

CC BY-SA 3.0
2016-08-25T11:32:09.020Z
Well, you need 3 coordinates of each body to determine their 3D-distance. The position on the celestial sphere gives you 2, then the third is distance.
So yeah, it is possible.  
But please don't ask for the exact method, else that sounds too much like a homework-question.
AtmosphericPrisonEscape
<star><distances>
Is it possible to calculate distance between two objects?
Sebastian Siemens
# Is it possible to calculate distance between two objects?

(Asked by: username_0 on 2016-08-25)

For example: I want to know the distance between Alpha Orionis (Betelgeuse) and Beta Orionis (Rigel). Is this possible? You only know the distance from Earth. May be this is a math problem and not an Astronomy question.

**Tags:** star, distances
> **Comments:**
> **username_1**: Well, you need 3 coordinates of each body to determine their 3D-distance. The position on the celestial sphere gives you 2, then the third is distance. So yeah, it is possible.   But please don't ask for the exact method, else that sounds too much like a homework-question.  

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## 1 answers

### Answer by username_2 on 2016-08-25. Score: 2

If you know the distance of each star from earth, and the angle between the stars, then you can us the cosine rule to find their distance from each other. See this for detail
<https://en.wikipedia.org/wiki/Law_of_cosines>


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