Question 1091261
<pre>
{{{drawing(400,320,-3,13,-3,9,
locate(3,4,A), locate(0,0,B), locate(5,0,C),
circle(9,4.5,.08),locate(9,4.5,K),
line(0,0,5,0), line(0,0,3,4),  green(line(-6,-3,18,9)) )}}}

Fold the paper forward so that AB coincides with BC.  That
means to fold it along the green line, but don't draw the
green line BK.  Let it just be "drawn" by the crease in the
paper.

The answer is that the fold line BK (the green line in the
drawing above) will be the bisector of the angle ABC.

Edwin</pre>