MathDB

12

Part of 1997 AMC 8

Problems(1)

1997 AJHSME #12 - Finding an Angle

Source:

6/30/2011
∠1+∠2=180∘\angle 1 + \angle 2 = 180^\circ
∠3=∠4\angle 3 = \angle 4
Find ∠4.\angle 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∘70^\circ",dir(35),NE); draw(arc(I,I+dir(250),I+dir(290),CCW)); label("40∘40^\circ",I+1.25*dir(270),S); label("11",J+0.25*dir(162.5),NW); label("22",J+0.25*dir(17.5),NE); label("33",L+dir(162.5),WNW); label("44",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∘<span class='latex-bold'>(A)</span>\ 20^\circ \qquad <span class='latex-bold'>(B)</span>\ 25^\circ \qquad <span class='latex-bold'>(C)</span>\ 30^\circ \qquad <span class='latex-bold'>(D)</span>\ 35^\circ \qquad <span class='latex-bold'>(E)</span>\ 40^\circ
AMC