jmc

Using the left triangle, we have: $\angle 1+70+40=180$ $\angle 1=180-110$ $\angle 1=70$ Using the given fact that $\angle 1+\angle 2=180$, we have $\angle 2=180-70=110$. Finally, using the right triangle, and the fact that $\angle 3=\angle 4$, we have: $\angle 2+\angle 3+\angle 4=180$ $110+\angle 3+\angle 4=180$ $110+\angle 4+\angle 4=180$ $2\angle 4=70$ $\angle 4=35$ Thus, the answer is $\boxed{35^{\circ }}$