This depends on what unit you are using to measure in. However, area will always be measure in (unit)^2.
You would use area. I would use the meter2. Okay
square units
The surface area of each side of the box ( there should be six sides unless it doesn't have a top ) added together will give you the total surface area. The surface area of one side is calculated by multiplying the length and the width. The answer will be in square inches or square centimeters depending on what unit of measure you use.
Square kilometres.
use a ruler to measure the sides then do length times width
First you need to decide what PROPERTY of the ear you want to measure: its length, its area, its mass, its surface area, etc.
Kelvin (K)
You would use area. I would use the meter2. Okay
square units
The surface area of each side of the box ( there should be six sides unless it doesn't have a top ) added together will give you the total surface area. The surface area of one side is calculated by multiplying the length and the width. The answer will be in square inches or square centimeters depending on what unit of measure you use.
Square feet. ************************* I would use centimetres to give the area in square centimetres.
Square kilometres.
square meter (m2)
acres, hectares, yards2, meters2, etc.
Metres, to measure its length or width, square metres to measure its area.
inches
lenght times width?