Geometry help with lateral area

[rachelmaddie]

For #15 I don’t know if I’ve applied the formula correctly
Rebecca’s jewelry box has 8 lateral faces and 2 bases.
Lateral area = perimeter of base x height
The perimeter of the base of the octagon:
2 x 8 = 16
Perimeter x height
16 x 5 = 80 square inches

 

[Dr.Peterson]

You're correct. Do you see that the lateral area is the area of a rectangle that could be wrapped around the side of the box?