Question

Determine whether the two figures are similar. If so, give the scale factor of the smaller figure to the larger figure.

Answer 1

4:12=1:3
7:21=1:3
18:54=1:3
ratios corresponding edges are the same (scale factor is the same) so these 2 figures are similar,
Answer  yes, 1:3

Answer 2

Yes they are similar and their scale factor is 1:3

7 * 3 = 21
4 * 3 = 12
18 * 3 = 54

Hope this helps :