I am going over it right now along with you guys, I just want to check if my work and the way I got the answer is right.

the answer would be 18, right?

Yes it is thank you for proving my answer to be right, this is my thought process

Here we go

Hi shteyas1,

I would have used a few more words like

And why exactly are those two triangles similar ?

BUT your logic is good.

Thank you, I will keep that in mind