Question

How do you figure out the scale factor from polygon A to polygon B?

Answer 1

Check the picture below.

the scale factor from A to B is the same scale factor from one side from A to a corresponding side on B, namely say

`\underset{\textit{corresponding sides of polygon B}}{\stackrel{\textit{sides of polygon A}}{\cfrac{2.5}{5}\implies \cfrac{2.5}{x}\implies \cfrac{2.5}{5}\implies \cfrac{1}{2}}}\impliedby \textit{scale factor of 1 to 2}`

let's find "y" in the same way

`\cfrac{2.5}{5}=\cfrac{1.5}{y}\implies 2.5y=7.5\implies y=\cfrac{7.5}{2.5}\implies y=3`

since we're assuming both polygons are similar, then that means all their angles are equal, as it shows in the picture.