Geomtry help will give medal and become a fan
HL means hypotenuse leg. Since you know the triangles are right triangles, and the hypotenuses are congruent, you need a statement that states that two legs are congruent.
You can eliminate choices A and B because they deal with angles, and we need sides. Now look at choice C. Are AC and DC legs? What about choice D. Are AC and BD legs?
would it be D?
Is BD the leg of a triangle?
AC and DC are legs of the two triangles. BD is not a leg.
That means the answer is not D.
so c than?
I wrote above you can eliminate A and B. Then I told you the answer is not D. That leaves only C. You are correct.