Jamie put 8 squares together to make a rectangle. there are 2 rows of squares each row has 4 squares . how many pairs of sides touch each other in the rectangle?

So,

Jamie has made a 2 x 4 rectangle, composed of squares.

Visualizing this setup, we can first see that the 4 squares lengthwise touch each other in pairs.  So that's 4 already.

In addition, notice that there are three columns in the widths.  Also notice that each column has 2 pairs of touching sides.  So 2 * 3 = 6 more pairs.

6 + 4 = 10

There are 10 pairs of sides that touch each other.