-- The angles in the lower left corner of each triangle are right angles, so the triangles are right triangles.
-- The angles in the lower right corner of each triangle are equal.
-- The slanted sides of both triangles are equal. (Since the triangles are right triangles, the slanted sides are their hypotenees.)
If the hypotenuse and one acute angle of a right triangle are equal respectively to the hypotenuse and one acute angle of another right triangle, that's enough to prove that the triangles are congruent.
Due to a formula limit, I cannot apply the visual product here but I assume you can easily do this part! I believe I will be switching over to paint.net to provide pictures of work for long division!
The length of ad would also have to be the three also. This is logically because ac and bd would be the two going across making them equal. This meaning to connect the lines together if they were parallel bc and ad lengths would be equivalent.