For this, we will be using Triangle Angle Sum Theorem (all interior angles in a triangle add up to 180°) for Triangle BCD. Since Angle CBD and BDC are congruent to each other and Angle BDA, we can solve for those two angles to get that angle. Our equation will look like this:
Firstly, subtract 35 on both sides of the equation:
Next, divide both sides by 2 and your answer will be 72.5 = x.
Since Angle CBD and BDC are 72.5°, this means that Angle BDA is 72.5° as well.