Explanation:
The rule is that
cos(x) = sin(y)
only if x+y = 90, where x and y are angles in degrees. In this case, x = 63 and y = 27, so x+y = 63+27 = 90, which fulfills the requirements needed to use the equation above.
Therefore,
cos(63) = 0.45 leads to sin(27) = 0.45
