the shortest distance from a point in an object, be it curve or a straight-line or else, is the distance from that point to the perpendicular to that line, so hmm in this case from W to the XZ it'd be at the perpendicular spot at Y, so hmm that line is just YW or WY, either way will work.
Now, in a right-triangle, the slanted line is always the longest of all three, so in this case in the △WYZ the longest line is the 19 or WZ. So we can say that whatever "x + 8" is, it must be smaller than 19 or less than 19.
x + 8 < 19
x < 11