Question

Given: Isosceles triangle ABC with CA congruent to CB. CD is the Altitude to AB .
Prove: triangle ACD congruent to BCD
Picture in the comments

Answer 1

Since CD is the bisector of AB, you know that AD and DB are the same length.
Also, you can use Pythagorean theorem, where the hypotenuse and the one side are of equal length on both triangles, therefore the 3rd length must be the same for both.

Answer 2

so its SIDE SIDE SIDE??

Answer 3

Yes.

Answer 4

THANKS SO MUCH @xGuardians