The answer would be 55 degrees
Step by Step:
Having two triangles to be isosceles because they have lines in two lines we should know that they should have two equal angles in the base which makes the triangle easiest to find. With that we should also know that triangles equal 180 degrees no matter their sizes and shape. So for the first big triangle, they have 55 degrees on one angle and is an isosceles, which would make the other side 55 degrees as well, so the equation would be 180 - 55 - 55 and will give you x which is 70 and will also be to the other triangle as it has a vertical angle to the smaller triangle making it also 70 and will have the two other angles equal as they are also an isosceles triangle. So it will be 180 - 70 = 110 / 2, which gives y = 55 degrees