cosine = adjacent / hypotenuse
if cosine B = 255 / 257
then adjacent = 255
and hypotenuse = 257
sine = opposite / hypotenuse
sine (A) = 255 / 257
sine (A) =
0.9922178988
Looking up the arc sine of
0.9922178988
we find that it is 82.847 Degrees
Angle A = 82.847 Degrees
