Final answer:
The correct definition of area is the amount of space an object covers on a flat surface, measured in square units according to the shape's specific area formula.
Step-by-step explanation:
The correct definition of area is the amount of space an object covers on a flat surface. This is essential in mathematics for various applications, such as measuring the size of a piece of land, the surface of a table, or any two-dimensional surface. Therefore, the answer is d. the amount of space an object covers on a flat surface.
When calculating the area, the measurement is typically in square units, such as square meters (m²), square feet (ft²), or square inches (in²), depending on the context. The area provides a clear indication of how much two-dimensional space is enclosed within the boundaries of a shape. For example, the area of a rectangle is found by multiplying its length by its width, and the area of a circle is determined by π times the radius squared.