Answer:
x = 45 degrees
Explanation:
If BD = CD, then the triangle BDC is an isosceles. So, angle DCB and angle DBC = (180 - 20) / 2 = 80 degrees.
From the above identification, all we need is the measure of angle DCB, since it is also an angle in the bigger triangle. Now, it is given that angle BDC = 20 and angle ADB = 35. Note that these two are adjacent, so add them to find the 2nd angle of the bigger triangle: 35 +20 = 55.
Now that we have the measures of the 2 angles, find angle 3(x) = 180 - (55+80) = 180 - 135 = 45.
Thus, angle x = 45
Hope this helps.