What is the formula to find the area A of a rectangle?

The area of a rectangle is calculated using the formula that involves multiplying the length (l) by the width (w): A = lw. This relation is grounded in the definition of area, which represents the amount of space contained within the boundaries of a shape. In the context of a rectangle, the area is derived from its two dimensions; the length giving one side of the rectangle and the width providing the other. Therefore, when you multiply these two values together, you effectively count all the unit squares that would fit inside the rectangle, thus yielding the total area.

The other options present different calculations that do not represent the area of a rectangle. The first option adds length and width, which does not yield a relevant measurement of area. The third option calculates the perimeter of the rectangle, which is the total distance around it rather than the space within. The last option subtracts width from length, which does not correspond to any common geometric formula regarding the properties of a rectangle. This understanding of rectangles and their measurements is fundamental in both geometry and various applications in real-life scenarios.