Answer: HL
Why?
Because we have two right triangles with the same shared leg (the L of HL) and the hypotenuses are the same length (the H of HL). The tickmarks tell us those segments are the same.
HL only applies to right triangles because the hypotenuse is only found in right triangles. If we didn't have those 90 degree square markers, then this would be an SSA case, but that's not a valid congruence theorem.
