A rectangular sheet of paper ABCD, with |AB| > |AD|, is folded so that two diagonally opposite corners A and C coincides - and the crease thus formed has length 5*|AD|/4.
Let E be a point on side AB such that segment DE
is parallel to the crease (perpendicular to AC).
Clearly, triangles ABC and DAE are similar
since corresponding sides are perpendicular.
------ = ------
|DE| = -------------
Combining this with the given:
|DE| = (5/4)*|AD|
|AB| = (4/5)*|AC|
===> |AD| = (3/5)*|AC|
===> |AB|/|AD| = 4/3
Posted by Bractals
on 2016-06-17 14:11:59