Two figures are similar with a similarity ratio of 4 and one side of the figure is 3 cm long. Find the lenght of the side of the similar figure.

I don't really know if I have to try to do it like an equation or if there's a formula for this.
Sorry if anything's wrong, I'm spanish, but I study math in english.

3 answers

if the ratio is 4, then the similar figure has lengths 4 times as big as the original.

4*3 = 12
I actually did that but I thought it was really simple and easy, haha.
Thank you so much.
oh, you can complicate it up a bit by using a proportion:

x/3 = 4/1

but this one is in fact pretty simple.