Dilations and Similar Polygons
Betzaida Martinez
Similar Polygons
Similar polygons are polygons that have congruent angles and corresponding sides that are proportional to one another. It is important to know how to identify similar figures because they can be used in real world situations like finding the height, width, or length of something.
Scale Factor as a Ratio
A ratio shows the relative sizes of two or more values. Each pair of corresponding sides of similar polygons will have equal ratios. Scale factors are usually written as ratios but in some cases are written as fractions and can be found by diving the larger side length by the smaller length.
Similar Figures - Similar Polygons - MathHelp.com
As we can see these statues are identical in shape but different in size making them similar polygons with the same scale factor.
The human pupil is a perfect example of similar figures and also dilation. Even though the size of our pupils change to larger or small depending on how much one is forcing their vision the pupil maintains the same scale factor.
According to this picture these polygons have a scale factor of 1/2. They are the same shape but polygon FGHE has been dilated to double the size of polygon BCDA.
The polygon in this picture also have a scale factor of 1/2 but notice how the angles remain congruent even after the dilation.