Do you mean the perimeter?? If so, that involves adding up the length of all four sides :)
You can measure it.
We can use either meter or centimeter to measure a rectangle. For a large area of rectangle we can also use "feet" or " yards". Using "meter" is a convenient form to measure the length of the rectangle.
measure it
measure them.
Yes, the length of a rectangle is generally understood as the longest side(s).
Given what? Probably measure it
You measure it.
Conventionally, it would be the measure of the longer sides.The length is that of its longest side.
For a rectangle, length X width = area. Measure the length in cm. Measure the width in cm. Multiply the length X the width to get the area in cm2.
You would multiply the length by the width.
A ruler can be very helpful in that situation.
If you do not know the length or breadth of a rectangle, you cannot know the area. If you do not know the area of a rectangle, you cannot know the length and breadth. To know the length and breadth of a rectangle, you have to know some other contributing factor in the equation. If you don't, measure it!