Answer
m$\angle$4=50$^{\circ}$
Work Step by Step
m$\angle$1+m$\angle$2+m$\angle$3=180
70+30+m$\angle$3=180
m$\angle$3=80$^{\circ}$
m$\angle$ACE=180-m$\angle$3
m$\angle$ACE=100$^{\circ}$
2m$\angle$4=m$\angle$ACE
2m$\angle$4=100
m$\angle$4=50$^{\circ}$
