Usually in meters (m)
meter
you need length and width length multiply width = area length + length + width + width = perimeter
To find the relationship in width and area you can use the formula area/length = width. To find the area of a room you multiple the length by the width.
lxwxh length times width times height
To find the width of a rectangle, you can use the formula for the area, which is Area = Length × Width. If you know the area and the length, you can rearrange the formula to find the width: Width = Area / Length. For example, if a rectangle has an area of 50 square units and a length of 10 units, the width would be 50 / 10 = 5 units.
a yard stick
You would use meters.
millimetres
meter
centimeters
I would go with millimetres
you need length and width length multiply width = area length + length + width + width = perimeter
the tool used to find the width of a pencil is a ruler. But use the centimeter side of it for the width only!!
Multiple the length by the width by the height
To find the relationship in width and area you can use the formula area/length = width. To find the area of a room you multiple the length by the width.
lxwxh length times width times height
It depends on what shape. For a cube, multiply the length by the width by the height.