Surface area is always measured in square units. When we talk about the surface area of a shape or object, we are referring to the total area of all its exposed surfaces. This includes the area of each individual face or side, as well as any curved or rounded surfaces.
For example, when we measure the surface area of a cube, we find the area of each of its six faces and add them together. Since each face of a cube is a square, the surface area is always measured in square units. This is because we are measuring the area of a two-dimensional shape (the face) that is repeated six times in the cube.
Similarly, when measuring the surface area of a rectangular prism, we find the area of each face (which is a rectangle) and add them together. Again, the surface area is measured in square units because we are measuring the area of two-dimensional shapes that make up the exposed surfaces of the prism.
The same principle applies to other shapes and objects as well. For example, the surface area of a sphere is measured in square units because we are measuring the area of the curved surface. The surface area of a cylinder is also measured in square units because we are measuring the area of the curved sides and the circular bases.
Surface area is always measured in square units because it represents the total area of all the exposed surfaces of a shape or object. Whether the surfaces are flat or curved, the area is still measured in square units to indicate that it is a two-dimensional measurement.