year 11 3D trigonometry question (1 Viewer)

[JamesGoh]

In the Grove textbook, maths in focus book 1, Im having difficulty trying to solve Exercise 6.14 question 9.

I've attached a document below stating the question, showing my attempt at the solution and the actual answer.

Can anyone point out what Im doing wrong?

cheers

 

[WrittenLoveLetters]

I think you should post this in the Preliminary section, it might get more attention because its pretty active in there too .

I'm actually going to start 6.14 today/tomorrow.

 

[laters]

http://puu.sh/h5tGY/a4d5eeeb27.png

My solution but not sure if it is the fastest.

Your problem may have been that you assumed the hypotenuse in the cylinder was horizontal, which it is not.

 

[Ambility]

Here's my solution. Basically I calculated the angle the bigger angle marked and subtracted the angle from it to get angle .

http://i.imgur.com/uQNUs4e.jpg

EDIT: Aaannnnddd.... I just realised I incorrectly rounded my last answer. Please ignore that mistake, the method is still correct.

 

[carolX]

I proved the similarity between two triangles and use the ratio to calculate the angle.

 

[Crisium]

In the Grove textbook, maths in focus book 1, Im having difficulty trying to solve Exercise 6.14 question 9.

I've attached a document below stating the question, showing my attempt at the solution and the actual answer.

Can anyone point out what Im doing wrong?

cheers

lawl enigma pls