ABCD is a parallelogram, which means that:
-The opposite sides are parallel, so AB || DC and AD || BC
-The opposite sides are congruent, so AB=DC and AD=BC
-Opposite angles are congruent
-Adjacent angles are supplementary
The congruent sides are equal which means that:
[tex]\begin{gathered} AD=BC \\ 2x=6 \end{gathered}[/tex]
1) From this expression, you can determine the value of x, you have to divide both sides of the equal sign by 2:
[tex]\begin{gathered} \frac{2x}{2}=\frac{6}{2} \\ x=3 \end{gathered}[/tex]
2) The opposite angles are equal, which means that ∠C=∠A=113º
3) Lines AD and BC are parallel lines intersected by a transversal line DB, so that:
∠CBD and ∠ADB are alternate angles, which means that they are congruent, so ∠CBD=∠ADB=35º
