Assumptions for similarity?

Hey guys,
I just did a non-calc GCSE maths past paper and there was a similarity question that said ‘state any assumptions you make’.

I’m not sure what it means and I couldn’t figure it out from the mark scheme either. I’ve attached both the question and answer. Thanks

If a pair of triangles are similar then they have the same angles.

You need to make assumptions about which angles are equal.