Freedom is the power,or rather right to act,speak,think as one wants.
Happiness is an emotional state that comes with joy,satisfaction,fulfillment and many other positive emotions.
Come to think of this two things: power/Control and positive emotions. You will realize that they perfectly work together.
Happiness is a complicated subject because everyone is different.But if there is a common thing in happiness is that people want to control their lives.Period.
The ability to do what you want,when you want,with who you want,for as long as you want is priceless.To me that is happiness.
Give me your thought.