Question 475686
If the problem was {{{ cos(30*pi/5) }}}, that equals
{{{ cos(6*pi) }}}. Even multiples of {{{pi}}} equals
{{{0}}} degrees. There is a {{{ pi/5 }}} left over, so
the angle is in the 1st quadrant, and cosine is positive.
{{{ pi/5 = 36}}} degrees.