Final answer:
The scale factor of the side lengths is 2/5.
Step-by-step explanation:
The scale factor is determined by comparing the areas of the two similar octagons.
The ratio of their areas is equal to the square of the scale factor. In this case, the ratio of the areas is 4m2/25m2.
Simplifying this ratio, we get 1/6.25.
To find the scale factor, we take the square root of the ratio.
Therefore, the scale factor of their side lengths is 1/2.5 or 2/5.
This means the side length of the smaller octagon is multiplied by 2/5 to get the side length of the larger octagon.