is it illegal in basketball to throw the ball at...

The ball must hit the rim unless it goes into the basket hitting nothing but the net.
 
the ball must hit the rim or it is considered an air ball
 
It is never illegal to hit the backboard, only go over it. You can hit the backboard on a free throw, but if it doesn't hit the rim on your second/last shot it will automatically go to the other team.
 
Back
Top