## anonymous one year ago The moon forms a right triangle with the Earth and the Sun during one of its phases, as shown below:

1. anonymous

2. anonymous

A scientist measures the angle x and the distance y between the Earth and the Sun. Using complete sentences, explain how the scientist can use only these two measurements to calculate the distance between the moon and the Sun.

3. anonymous

This is my answer so far: The scientist should use the cosine function (cos = adj/hyp) because we already know the adjacent, and the hypotenuse is what we need to find. If we use cosine, we can find the hypotenuse while working with the problem.

4. anonymous

@ganeshie8

5. anonymous

Am I taking the right approach by using cosine?

6. triciaal

yes cos x = y/distance Moon to Sun

7. anonymous

Okay thank you! But, should I write anything else in my answer?

8. anonymous

$\cos(x) = (\frac{ y }{ hypotenuse })$

9. anonymous

And is this what you mean by "cos x = y/distance moon to sun"?

10. anonymous

Just want to make sure I'm writing it correctly.

11. anonymous

@triciaal are you there?

12. triciaal

yes and may want to include something about why this relationship right angle importance not sure how to word it

13. anonymous

Okay, but I'm not sure how to describe that. I just started doing trig. Can you give me a hint on what the relationship is?

14. triciaal

what I am getting at is why the cosine rule

15. anonymous

Oh, okay, but my class did not really teach me "rules" that relate to the trig functions. All they said was that cosine is the ratio of side adjacent the angle to the hypotenuse.

16. triciaal

|dw:1438189071435:dw|

17. triciaal

never mind the draw then you were told what I was getting at

18. anonymous

Oh, okay. I'm such a confused person, lol. Thank you!

19. triciaal

possible structured answer when we have a right angle triangle we know the cosine is ...... for this situation the cosine of the angle x is .......

20. triciaal

you are welcome