Question

The scale factor of two similar polygons is 4:5. The perimeter of the larger polygon is 120 ft. What is the perimeter of the smaller polygon?​

Answer 1

$\bf \cfrac{\textit{small polygon}}{\textit{large polygon}}\qquad \qquad \stackrel{\textit{scale factor}}{\cfrac{4}{5}}=\stackrel{\textit{perimeters}}{\cfrac{x}{120}}\implies 480=5x \\\\\\ \cfrac{480}{5}=x\implies 96=x$