Which pair of undefined terms is used to define the term parallel lines?

Can someone explain to me how to do

Taylor wants to paint his rectangular deck that is 41 feet long and 24 feet wide. a gallon of paint covers about 350 square feet. how many gallons of paint will taylor need to cover the entire deck? round your answers to two decimal places when necessary.

Which is the focus of a parabola with equation y2=4x