When calculating the perimeter of a figure, what type of units are used?

When calculating the perimeter of a figure, linear units are used because perimeter refers to the total length around a shape. Perimeter is a measure of distance, which inherently requires units that correspond to length, such as centimeters, meters, inches, or feet. These units express how long the sides of the figure are when added together.

In contrast, volume units are used for three-dimensional measurements, weight units measure mass, and decimal units do not specifically pertain to a type of measurement but rather express numbers in the decimal system. Therefore, linear units are the appropriate choice for measuring perimeter, as they directly relate to the one-dimensional measurement of length.