The lengths of the links of four-bar linkage ABCD comply with the conditions: A͞B=D͞C and B͞E=C͞E=0.5sqrt(4A͞B²+A͞D²-2A͞D(A͞D-B͞C)). When link 1 turns about fixed axis A, point E of link 2 describes a path of which a cer tain portion approximates straight line q-q, passing through points A and D.
$661$LW,GI$