richiesmasher
Junior Member
- Joined
- Dec 15, 2017
- Messages
- 111
Hello, I have two images here, the first of which is a diagram of the question below it.
So as you can see from the question they want the length of NP.
Now In my diagram, I equated the angle of depression of L to N, as 28.7 degrees on the right angled triangle with hypotenuse 9m.
Now from Here, I've been trying various methods to figure out the length of NP.
I first tried, Sine28.7degrees= Np/9m
So: Sine28.7 x 9 = NP = 4.32m.
I then tried adding all the angles in that triangle, to get the unknown angle.
We have 28.7+90 = 118.7 degrees
SO therefore the other angle is = 180-118.7 degrees = 61.3 degrees.
Now using this, I did, Sine61.3 = LP/9
= Sine61.3 x 9 = LP = 7.89m
Then using my two known sides 7.89m and 9m, I used pythagoras' theorem to solve for NP
92-7.892 = NP2
NP= 4.32.
However the answer in the book says NP = 7.89m.
Which is the answer that I got when I calculated LP.
So I'm quite confused about what could be going wrong here.
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