The figure to the right shows two parallel lines intersected by more than one transversal. Let x=42. Find the measure of angles 1,2,and 3.
Since the lines are parallel, we know that corresponding angles are congruent. Angle $2$ and angle $4$ are corresponding angles, so they have equal measures. Since we are given that $x=42$, we know that the measure of angle $2$ is $42$. Angle $2$ and angle $3$ form a linear pair, so their measures add up to $180^\circ$. Since angle $2$ measures $42^\circ$, angle $3$ must measure $180^\circ - 42^\circ = \boxed{138^\circ}$. Finally, angle $1$ and angle $2$ form a linear pair, so angle $1$ must measure $180^\circ - 42^\circ = \boxed{138^\circ}$. [asy]
pair A,B,C,D;
A=(0,8);
B=(0,-8);
C=(3,8);
D=(5,-8);
draw(A--B);
draw(C--D);
label("$1$",(0,5));
label("$2$",(0,-1.5));
label("$3$",(5,-1));
label("$4$",(5,4));
[/asy]