If the side of a square is r+s, what does s² show in its model?

Correct answer: The area of the small s-square

The direct answer is C: the area of the small square whose side is s. In the model for a square with side r+s, each side is split into lengths r and s. This creates four regions: an r-by-r square with area r², two rectangles each with area rs, and an s-by-s square with area s². Since the two dimensions of the last region are both s, its area is s×s = s². Option A is incorrect because the two rectangles together have area 2rs, not s². Option B describes the large square with side r and area r². Option C correctly identifies the small corner square with side s. Option D is also incorrect because s² is an area, while perimeter is a length measurement and would involve adding side lengths. The important distinction is that a squared term usually represents the area of a square whose side has that symbol. Memory cue: same side multiplied by itself gives a square area: s×s = s².