California Assessment of Student Performance and Progress (CAASPP) Math Practice Exam 2025 - Free CAASPP Math Practice Questions and Study Guide

Area is defined as the measure of the interior of a plane figure in geometry. This concept refers to the size of a two-dimensional surface, usually quantified in square units, such as square inches, square feet, or square meters. When calculating the area, one determines how many square units can fit within the boundaries of the figure. For instance, for a rectangle, the area can be calculated by multiplying its length by its width, demonstrating how many unit squares can be accommodated within that shape.

The other options refer to different geometric concepts. The distance around a closed figure describes the perimeter, which measures the total length of the boundary. A relationship between two equal expressions refers to equations or equalities in mathematics, and the sum of the lengths of the sides of a polygon also pertains to the concept of perimeter rather than area. Thus, the option defining area accurately captures its essence in geometry.