Why does Juliet tell her father she is willing to marry Paris?

Juliet had a plan with friar to go home, agree to the marriage, and then go in her room and drink a postion that makes her seem dead for 48-72 hours. she would be burried and then wake up in the timb with romeo by her side. everyone would think shes dead, and she would happily be with romeo

Why does Juliet tell her father she is willing to marry Paris?