If that is the question, we solve this with one ratio.
First, we need to choose only one side from both grafics.. it has to be the same side, for example... I'm going to do a graphic:
We are gonna paint in blue two similar sides, in this case the side from A to D will be similar to the side from M to P. We extract the values from question and do the ratio of this way:
And your answer is 3/2