Question: how do you do length and width?
Answer: The area of a rectangle (A) is related to the length (L) and width (W) of its sides by the following relationship: A = L ⋅ W. If you know the width, it's easy to find the length by rearranging this equation to get L = A ÷ W. If you know the length and want the width, rearrange to get W = A ÷ L.