So first of all they are similar because they are in the same degree and the top and bottom of each one is equal, and so are the left and right. You need to set up a proportion of 10:3.12 and 5:1.2 because those are the sides that match up. They match because if you rotate the second figure to the right it would match the figure on the right. The only available answer then out of 10:3.12 and 5.12 is letter A. Hope this helps comment if you need any more help or it’s confusing.
The set A U B is represented by shading both circles A and B (also the overlapping region as well). Any point in set A U B will be in either A, B or both.
