If two triangles are similar, what must be true about their corresponding side lengths?

1. The rule for similar triangles says their corresponding angles are equal and their corresponding sides are in the same ratio. 2. This ratio can be any scale factor, so the side lengths do not need to be equal to each other, only proportional. 3. The 180-degree total applies to the angles inside one triangle, not to a comparison between the sides of two similar triangles. _Source: OpenStax Prealgebra (CC BY 4.0), Ch 9 "Math Models and Geometry", section 9.3 Use Properties of Angles, Triangles, and the Pythagorean Theorem_