Respuesta :

[tex]\bf 1:1.618\iff \cfrac{1}{1.618}\cfrac{\leftarrow \textit{small side=width}}{\leftarrow \textit{longer side=length}}\\\\ -----------------------------\\\\ \textit{now, what if the length is 35?}\to \cfrac{1}{1.618}=\cfrac{w}{\boxed{35}}[/tex]

solve for "w" to get the width

what's the area of a rectangle?   length * width, or lw