Find the area of the purple shaded region

When he was a young man Fidel Castro went to a Cuban psychic and asked if she could tell anything about him. The old woman looked at Fidel closely and declared, “You should avoid alcohol at all costs.
Because when you are drunk I predict that you will make waves, overthrow governments, and stir up revolution!”
She pointed at him, “So do not, under any circumstances, become inebriated!”