Answer: 10
Step-by-step explanation:
Since BD=CD, we know that angles BCD and CBD are equal. Thus, angle CBD = 30 degrees.
If angle CBD = 30 degrees, then angle ABD = 150 degrees because these 2 angles are supplementary.
Now, because the sum of the angles of a triangle is 180, x = 180 - 150 - 20 = 10.
