Before the invention of the electronic calculator, mathematicians spent most of their time creating tables of numbers indicating huge numbers of values of sin, cos and tan for various angles.
Today, thanks to the physicists who invented the micro-processor, we can instantly find sin, cos and tan ratios after punching a few buttons. Type this:
[sin]   [=]
You should get the answer 0·5
Some calculators expect you to type the number before you tell it what to do with it. In which case, try:
  [sin]