How do you find the perimeter of a quadrilateral with equations used on the sides like " x+2"

 Area is a count of how many unit squares fit inside a figure. To fully understand this classic definition of area, we need to picture the unit square. A unit square is a square that is one unit long by one unit wide. It can be 1'x1', 1 m x 1 m, 1 yd x 1 yd, 1" x 1", ...

4should be the last one n=4

Ithink it’s b because it say 3 plastic rings and all the balls