Nah, the angle isn’t specified as a right angle. We can’t assume it’s 90° just because it’s drawn that way, because it isn’t drawn to scale.

Left triangle has 180° total. 60+40=100, which means that middle line is actually 80°, not 90. And since the opposite side is the inverse, we know it is 100° on the other side.

100+35=135. We know the right triangle also has 180° total, so to find the top corner we do 180-135=45. So that top corner of the right triangle is 45°, meaning x must be 135° on the opposite side.

It’s not unsolvable at all. The answer is x=135°. The triangles simply aren’t drawn to scale; The line between them isn’t a 90° angle, (even though it is drawn that way) because it is not specifically marked as 90° with a square angle mark.

But it’s not unsolvable, just a misleading drawing…