Your sock drawer only contains 18 white socks and 18 blue socks. How many times do you need to reach inside the drawer and take out a sock to guarantee a
matching pair?

3 socks

Step-by-step explanation:

If the first 2 socks are the same, that means you have a matching pair.

If the first 2 socks are different, then no matter what the third sock is, it will always matches one of the first 2 socks.

last option

step-by-step explanation:

given that δdef is right and isoceles,

assuming that side df is the hypotenuse means that de an ef are the other 2 sides that intersect at 90° and are of equal length.

because they are of equal length, we can say that they are congruent

because they intersect at 90°, their slopes must be opposite reciprocals.

only the last option satisfies these conditions.