Answer:
shortest: BC
second shortest: AB or BC (not enough info to tell which)
Explanation:
We need to find out which is the shortest and which is the second shortest of the four segments with lengths x, x + 9, 11, and 20.
We already know that x + 9 > x, and 20 > 11,
so BC < BD, and AB < BE
Look at the figure. Right triangle BDE has right angle BDE. That makes the other two angles of the triangle acute angles. The longest side of a triangle is opposite the longest angle. Side BE is the longest side of triangle BDE, so side BE must be longer than side BD, and 20 > x + 9.
20 > x + 9, or BD < BE
Subtract 9 from both sides.
11 > x, or BC < AB
BC < BD
AB < BE
BD < BE
BC < AB
Two possible orderings of the sides from shortest to longest are:
BC, BD, AB, BE
or
BC, AB, BD, BE
We know for sure that BC is the shortest, but there is not enough information to be able to place AB and BD with certainty in increasing order. The second shortest segment is either BD or AB.