Answer:
HL theorem
Explanation:
I have no idea what the colors mean, but the triangle is a right triangle and that means that the third side is known by using the Pythagorean Theorem.
Accordingly the HL theorem (hypotenuse Leg is what I think HL means), the two triangles are congruent. The angles can be shown to be equal as well, but the triangles are immediately congruent.
The question is not completely clear.