Answer
m$\angle$B=40$^{\circ}$
Work Step by Step
m$\angle$DAE+m$\angle$1+m$\angle$2=180
m$\angle$DAE+70+70=180
m$\angle$DAE=40$^{\circ}$
m$\angle$A=m$\angle$3+m$\angle$DAE+m$\angle$4
m$\angle$A=30+40+30
m$\angle$A=100$^{\circ}$
Angles 1 and 5 form a straight line so they are supplementary.
m$\angle$1+m$\angle$5=180
70+m$\angle$5=180
m$\angle$5=110
m$\angle$3+m$\angle$5+m$\angle$B=180
30+110+m$\angle$B=180
m$\angle$B=40$^{\circ}$
