##### Trigonometry story problem.

 Mathematics Tutor: None Selected Time limit: 1 Day

The tallest freestanding structure is the CN tower in Toronto Canada. From ground level the angle of elevation from point A to an object on the observation deck of the CN tower is 75 degrees. 111 feet away from point A, the angle of elevation is 70 degrees. Find to the nearest foot, the height of the observation deck of the CN Tower.

Jul 30th, 2015

using the sine rule,

we get the H=(111sin105)/sin5

=1230.19ft

so again we apply SOHCAHTOA formula

we have the height h=1230.19/sin70

=1309.14ft

Jul 30th, 2015

Thanks for helping me out! So I can start this correctly you mentioned starting off with law of Sines. So given the information is that

Sin75/x=Sin70/111 ? SinA/a = SinB/b

Jul 30th, 2015

Brilliant! That is exactly what I said and did. With that, you are headed to the right answer.

Welcome.

Jul 30th, 2015

From a 111 feet away from point A, the angle of elevation is 70 degrees. I did not write that in because it was worded weird to me...now I think it's a distance reference of a side..sorry if that added confusion.

Jul 30th, 2015

yes, away from point A ,is 111ft giving an angle of elevation of 70 degrees

Jul 30th, 2015

Okie dokie

Sin75(111) all divided by Sin70 = 114 feet. Is what I got

Jul 30th, 2015

And I kinda made a sketch, that 114 is the height of the building.

Jul 30th, 2015

Hmm, I'm gonna keep working on this one. Where did you get Sin105 and Sin5? Thanks for your patience lol

Jul 30th, 2015

ok, from 180-75=105, then 180-(105+70)=5, i hope you have seen that.

Jul 30th, 2015

it works well with a sketch, kindly redo the calculation, the answer becomes 1156ft

Jul 30th, 2015

I welcome all your maths problems, always send them to me.

Jul 30th, 2015

Perfect, I can get 1,309.14' now. And I think I understand why you did 180-75. = corner angle with a right triangle must =180. You took that difference and basically did the same thing to the other angle corner getting a degree of 5.

Jul 30th, 2015

exactly!

Jul 30th, 2015

You rock ty!!

Jul 30th, 2015

I assure you of grade A

Jul 30th, 2015

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Jul 30th, 2015
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Jul 30th, 2015
Dec 5th, 2016
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