A stop sign has the shape of an octagon with each side measuring 0.5 ft. To make a scale model of the sign, every dimension is multiplied by 1/20. How is the ratio of the areas related to the ratio of the corresponding dimensions? What is the ration of the areas?

Answer 1

area varies as the square of length dimension. (note square A = X^2, circle A = pi R^2)
If you multiply every length by 1/20, you multiply every area by 1/400