There are a lot of discrepancies in the answer key and so I had wanted to verify with another eye if I am correct on this or not.
The question simply relates to a pipe going down the side of a cliff with two bends in it, the second steeper than the first.
From flat ground, pipe bends 17 degrees (angle of depression) and is 6.4m long.
Pipe bends down again (37 deg "from horizontal" it says) and is 5.2m long.
How far down has the pipe gone vertically to the nearest metre?
I saw what worked and went with it. Two right triangles at each level, and a cosine (have hypotenuses, adjacent will = height, so use cosine)
6m + 4m = 10m, however the answer key says 5 metres. There are many flaws in the answer key (them not rounding as instructed in the worksheet giving varying answers) however this one seemed a lot different than a simple rounding issue. Do you see anything wrong with either?
cos(17) = 0.9563, ..., 6.4*0.9563 = 6m
cos(37) = 0.7986, ..., 5.2*0.7986 = 4m