my living room is 15`×21` my hall way is 3`×10` how much will it take to fill this area?

Question

What is the total square footage I need

Answer 1

Area of a square or rectangle is length times width.

 So, A=L*W=15*21=315 square feet for the living room

 And, A=L*W=3*10=30 square feet for hall way

Sum of the two is 345 total square feet.