Problem Statement
∠1+∠2=180∘∠3=∠4Find ∠4.[asy]pair H,I,J,K,L;
H = (0,0); I = 10*dir(70); J = I + 10*dir(290); K = J + 5*dir(110); L = J + 5*dir(0);
draw(H--I--J--cycle);
draw(K--L--J);
draw(arc((0,0),dir(70),(1,0),CW)); label("70∘",dir(35),NE);
draw(arc(I,I+dir(250),I+dir(290),CCW)); label("40∘",I+1.25*dir(270),S);
label("1",J+0.25*dir(162.5),NW); label("2",J+0.25*dir(17.5),NE);
label("3",L+dir(162.5),WNW); label("4",K+dir(-52.5),SE);
[/asy]<spanclass=′latex−bold′>(A)</span> 20∘<spanclass=′latex−bold′>(B)</span> 25∘<spanclass=′latex−bold′>(C)</span> 30∘<spanclass=′latex−bold′>(D)</span> 35∘<spanclass=′latex−bold′>(E)</span> 40∘