#### Answer

m$\angle$3=35$^{\circ}$

#### Work Step by Step

Line DB bisects $\angle$ADC so $\angle$1 and $\angle$2 are congruent. Angles 2 and 3 are alternate interior angles so they are also congruent. According to the transitive property, this means that angles 1 and 3 are congruent.
m$\angle$1=m$\angle$3=x
m$\angle$A+2x=180
110+2x=180
2x=70
x=35
m$\angle$3=35$^{\circ}$