3D trig (1 Viewer)

[Alexander Max]

Can any one help me get started on this question please?
Im not sure which way to tackle it :S

Point A is due east of the turbine and the angle to the top of the turbine is 42degrees. you move south by a distance of 20M to point B and measure the angle to the top of the wind turbine to be 37degrees.
What is the height of the turbine?

I made my self a diagram for it as well

 

[klee98]

I've seen this before, and I'm pretty sure you're missing an angle.
Anyways, use sine rule to find the sides (leave it as an unknown) and then use cosine rule to find h

 

[Alexander Max]

There are no other angles given , only the angles i can work out (all angles in a triangle must =180)
therefore 180 - (90+42) = 48 and 180 -(90+37) = 53

How can i use sin and cosine when i only know that one length + the two angles with no associated legnths?

 

[Alexander Max]

Here is the full question and you can point out if I'm missing anything

 

[Librah]

h=27.5? you should get h^2= 400/ (1/tan^2(37) - 1/tan^2(42) ) unless i've made some kind of mistake. BAC is 90 degrees since it's given that it's due south of A.

 

[Alexander Max]

Yes i think that works!
Thank you for your help!

 

[Dragon bomb]

Your well come mate !!!!


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[turntaker]

I'll give you some help with 3D trig. Express everything in terms of cos and sine and express everything one plane.

 

[ishfish]

its pythagoras theorem