How can the surface area in acres of a lagoon primary cell that is 400 feet by 150 feet be calculated?

To determine the surface area of a lagoon primary cell measured in feet, the formula for area is indeed based on multiplying the length by the width. In this case, the lagoon has a length of 400 feet and a width of 150 feet.

The formula used, which states that the area equals the length times the width, perfectly aligns with the standard geometric formula for calculating the area of a rectangle. By employing this formula, you can find the area in square feet. To convert this area from square feet to acres, it would be necessary to divide the resulting square feet by 43,560, as there are 43,560 square feet in one acre.

When evaluating the remaining options, they either misrepresent the method of calculating area (as with addition or averaging), or suggest an incorrect multiplication that does not apply in this context. Thus, the multiplication of length and width provides the correct method for calculating the area of a rectangular surface, making it the appropriate approach for this question about the lagoon's surface area.