To find the area of a square or a rectangle, you would multiply the value of the length by the value of the width.
length x width = area
1. Measure the length of the paper (the length, in this case, is the longest part of the paper).
2. Measure the width of the paper (the horizontal, shorter part of the paper).
3. Multiply said values together to find the area with your chosen system of units.
However, if you are looking for exclusively the length and/or width, you can use a ruler to find said dimensions.
