What formula is used to calculate the perimeter of a rectangle?

The formula used to calculate the perimeter of a rectangle is derived from the understanding that the perimeter is the total distance around the rectangle. A rectangle has two lengths (L) and two widths (W). To find the perimeter, you would add the lengths and widths together:

1. First, you add the length and width (L + W), which gives you the sum of one complete side and the adjacent side.

2. Since a rectangle has two identical lengths and two identical widths, you need to multiply this sum by 2 to obtain the total distance around the rectangle, leading to the formula (L + W) x 2.

This explains why option B reflects the correct calculation process, as it sets the foundation for understanding the relationship between the sides of a rectangle and their contribution to the overall perimeter.

Further, the perimeter can also be expressed with another formula, 2L + 2W, which simplifies to the same result as (L + W) x 2, but is not identical to option B as presented. The choice that directly addresses the process of calculating the perimeter using the sum of both dimensions is thus the most appropriate.