## MaryJSmith 3 years ago What is the length of the portion BC of the cloth?

1. MaryJSmith

2. MaryJSmith

8cos35 degrees 8sin 35 degrees sin35 degrees/8 cos35 degrees/8

3. saifoo.khan

use sin ratio.

4. MaryJSmith

idk what that is..

5. saifoo.khan

$\sin \theta = \frac{opposite}{hypotenuse}$

6. MaryJSmith

idk what all that means..

7. saifoo.khan

|dw:1333128731997:dw|Dont sleep in class. ;)

8. MaryJSmith

I'm home schooled.. I can't sleep in class , haha . I just don't understand this stuff & I have HORRIBLE memory :) Ha !

9. saifoo.khan

lol. Ok. this is easy i can teach you. :)

10. MaryJSmith

So what is it exactly that I'm supposed to do here ??

11. saifoo.khan

There are three basic ratios. Sin ratio, cos ratio, tan ratio. you have to remember these.. Not them down somewhere.

12. MaryJSmith

okay..

13. saifoo.khan

|dw:1333128936512:dw|

14. saifoo.khan

|dw:1333129034555:dw|

15. saifoo.khan

Now these are the three sides. now it depends upon the question which two ratio you have to use.. you have to judge it by yourself.

16. saifoo.khan

Now in your question.. you are given hypotenuse and you have to find the opposite side.. so u will be using sin ratio.

17. MaryJSmith

i still don't get it though . like , what #'s do i plug in & where ?? it's so confusing to me!!

18. inkyvoyd

Ok, so the basic idea is that if you have a right angle, and You know the second angle, you know the ratio of the two sides. Now all of the trig functions essentially take in an angle, and out put a ratio.

19. MaryJSmith

i'm still confused :(

20. inkyvoyd

Do you want to talk it over in chat?

21. MaryJSmith

No.. too overwhelming . Just mssg me .

22. inkyvoyd

Can we do something like tiny chat? Messaging is too slow. If you have a skype, you could chat with me there (or create an anonymous one)

23. MaryJSmith

i cant , im also takin a test & i can only be on here & my test (im bein supervised)

24. inkyvoyd

Wait, you are allowed to go here and on your test?

25. MaryJSmith

Yes

26. inkyvoyd

Alright, Trigonometry is like an extension of triangle congruence.

27. inkyvoyd

*triangle similarity

28. inkyvoyd

For triangle similarity, we can prove that two triangles are similar given certain info (SAS, AA, SSS, etc). But if they are similar, then how can we figure out the side lengths they have?

29. MaryJSmith

idk..

30. inkyvoyd

The answer is that we use trigonometry. The basic idea of trig is that in a right triangle where we know all the degree measures, we can determine the ratio between the sides.

31. inkyvoyd

Tell me if you are following what I'm saying, ok

32. MaryJSmith

I'm not.. haha sorry . I am so confused !! I'm a visual/audio learner..

33. inkyvoyd

ok, who is supervising you? I have file that will help you a lot, but it's for a geometry software called "GeoGebra"

34. MaryJSmith

i have geogebra

35. inkyvoyd

Alright, take a look at this file. Tell me if it helps.

36. MaryJSmith

I'm just gonna guess cos theres like 4 or 5 probs like this & I have 15 mins to finish 20 more problems !!!!!

37. inkyvoyd

sigh. if they are typable, put them into wolfram alpha dot com or something,

38. Mikellaalbertson