How to answer question no .1 ?

Question

1346 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-07-28T14:06:33

I got A.

I considered the diagram:

enter image source here

where I added some information to help the resolution.
Let us consider triangle HJK. From trigonometry we get:

#9/(HK)=tan(35^@)#

so that:

#HK=9/tan(35^@)=12.85m#

Now consider triangle HPK, we get:

#13/(HK)=tan(alpha)#

and:

#alpha=arctan(13/12.85)=45.3^@#