Which measurement describes the boundary length of a polygon or shape?

• A. Area
• B. Perimeter
• C. Circumference
• D. Volume

Answer: (B)

The boundary length of a polygon or shape is the perimeter. Perimeter sums all the side lengths along the outside edge, giving how far you would walk if you went all the way around the shape. For common shapes, you add each side length; for a rectangle, that’s 2 times the sum of its length and width. For example, a rectangle 4 units by 3 units has a perimeter of 4 + 3 + 4 + 3 = 14 units. Area, by contrast, measures how much space is inside the shape (square units). Circumference refers specifically to the boundary around a circle (though it’s the idea of boundary length for curved shapes), and volume measures how much space a 3D object occupies (cubic units). Therefore, the boundary length of a polygon is described by its perimeter.