Similar triangles A and B have the property that their corresponding side lengths have the same ratio.
For the first triangle, the side lengths are 3 cm, 6 cm, and 9 cm.
For the second triangle, the corresponding side lengths are 6 cm, 12 cm, and 18 cm.
It's apparent the side lengths of the second triangle are double the side lengths of the first triangle, so they are similar.
True