What is the surface area of a piece of pipe that is open at both ends, has a radius of 6 inches, and a height of 18 inches? (use 3.14 for π.)

Aka lateral area

you can imagine it like this:
imagine you take a sheet of paper and roll it into a tube
the lateral aera=circumference times height because if yo open the paper, the area is legnth times width, and when you roll it up, width turns into circumference

so

LA=h(circumference0
LA=h2pir
LA=18*2*pi*6
LA=216pi
pi=3.14 for this question
LA=678.24

SA=678.24 in²