What is the formula for the area of a rectangle?

The formula for the area of a rectangle is indeed represented as the product of its length and width, denoted mathematically as lw. This formula arises from the fundamental property of rectangles, where the area is determined by how much space is enclosed within its four sides. When you multiply the length (l) by the width (w), you effectively count all the square units that fit within the rectangle.

In contrast, options that suggest addition or perimeter calculations, such as the sum of length and width or twice their sum, are not relevant to measuring area. The last option, which equates length and width, suggests a square rather than a general rectangle. Therefore, understanding that area is specifically measured by multiplying these two dimensions clarifies why the correct answer focuses solely on the multiplication of length and width.