In the triangle ABC, the angle c = 90 degrees, BC = AC = 2, D is the midpoint of the AC side, find sin angle, Tan angle DBA

In the triangle ABC, the angle c = 90 degrees, BC = AC = 2, D is the midpoint of the AC side, find sin angle, Tan angle DBA

We know that △ ABC is an isosceles right triangle, AB and BD can be obtained by Pythagorean theorem, and then sin angle DBA can be obtained by angle a = 45 ° and sine theorem. We don't know what sine theorem is? If the three sides of △ abd are determined, then all angles are also determined. For this problem, we can also do de through point D, perpendicular to AB, intersecting AB at point E, and get de and be