Question

the length of a rectangle is twice the width. the area is 512yds^2 find length and width

Answer 1

so.. hmm notice the picture below

since we know the length is twice "w" or 2w  then

$\bf A=(2w)(w)\qquad A=512\implies 512=(2w)(w) \\\\\\ 512=2w^2\implies \cfrac{512}{2}=w^2\implies \sqrt{\cfrac{512}{2}}=w$

what's the length? well, 2w