See attachment for reply and answer.
Answer: 
<u>Step-by-step explanation:</u>
cos x tan x - cos x = 0
cos x (tan x - 1) = 0
cos x = 0 tan x - 1 = 0
tan x = 1

[|] Answer [|]
<u><em>6, 5, 4</em></u>
<u><em></em></u>
[|] Explanation [|]
<em>Exterior Angles:</em>
<u><em>Angles facing outward on a triangle</em></u>
Angles 6, 5 and
4 are not inside the main triangle. They are wide open. <u><em>Exterior simply means the outside of something.</em></u> Angles 6, 5 and 4 are the outside angles to the main triangle.
<u><em>_[|] Eclipsed [|] _</em></u>