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-   -   Help with High School Maths hard question (http://mymathforum.com/geometry/345241-help-high-school-maths-hard-question.html)

 Jeff Shreeves November 1st, 2018 08:35 AM

Help with High School Maths hard question

1 Attachment(s)

 v8archie November 1st, 2018 10:04 AM

Do you know the cosine rule and the sine rule?

 skipjack November 1st, 2018 11:09 AM

1 Attachment(s)
Attachment 10008
The diagram above gives the angles, so you just need to show the remaining lengths are correct.

 Jeff Shreeves November 1st, 2018 12:29 PM

How did you find that you should use those angles and triangles?

 Jeff Shreeves November 1st, 2018 12:53 PM

Quote:
 Originally Posted by v8archie (Post 601856) Do you know the cosine rule and the sine rule?
yes

 v8archie November 1st, 2018 01:04 PM

Well you can use them to find all lengths and angles in the figue. I'd start with the cosine rule on the triangle with sides $\sqrt3$ and $1$.

 Jeff Shreeves November 1st, 2018 01:10 PM

I have done everything that I can I have done law of cosines and law of sines but I really can't find the answer could you please tell me the answer to the question.

 v8archie November 1st, 2018 03:01 PM

What did you get?

 skipjack November 2nd, 2018 09:09 AM

Quote:
 Originally Posted by Jeff Shreeves (Post 601862) How did you find that you should use those angles and triangles?
As the diagram was accurate, the angles could be measured directly, albeit approximately. The extra triangles were then obtained by inspection.

 Denis November 2nd, 2018 10:27 AM

Archie TOLD you how.