Round or square?

Sardar Santa Singh's son, Jolly, came home from school and declared, "We had a fantastic Algebra class today."

Santa Singh asked the boy, "Huh, what did you learn?"

Jolly answered proudly, "I know all about Pi R Square now."

Santa Singh reprimanded the boy, "Dont' try to take me for a ride boy. It's a known fact that pies are round!"