World's Hardest Easy Geometry Problem

The directions are there, but I'll post them:

The figure is at the link.Using only elementary geometry, determine angle x. Provide a step-by-step proof.

You may only use elementary geometry, such as the fact that the angles of a triangle add up to 180 degrees and the basic congruent triangle rules (side-angle-side, etc.). You may not use more advanced trigonomery, such as the law of sines, the law of cosines, etc. There is a review of elementary geometry below.

This is the hardest problem I have ever seen that is, in a sense, easy. It really can be done using only elementary geometry. This is not a trick question.

Have fun.

At first glance, my first thought was "that's trivial." But it's not. Many times I thought I had quick solutions, and I did not. Yall enjoy, and without wasting much more of my own time, I'm simply going to trust the mathematicians who have said elsewhere that it is genuinely hard.

I feel like a sham of a math tutor, now.

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