#### Answer

E: The ratio of lengths of corresponding sides in similar figures.

#### Work Step by Step

Recall, when we were trying to find the lengths of sides on similar shapes, we used scale factors to set up the relationship. For instance, we may say that 5/8=4/x, where x is the side that is missing. Because there is division, we know that "a ratio" is the right answer, for a ratio divides two things to establish a proportion.