Question

Please help !

Answer 1

@satellite73 @bahrom7893

Answer 2

\[\cos(x)=\frac{8}{21}\]
\[x=\cos^{-1}(\frac{8}{21})\] and a calculator

Answer 3

i dont have a calculator it died

Answer 4

of course you have a calculator. you are on a computer!
http://www.wolframalpha.com/input/?i=arccosin%288%2F21%29

Answer 5

so my answer is 67.6

Answer 6

@satellite73