If I am given the length of DF in the parallelogram DEFG, I can find the length of DK by dividing DF by 2. The reason being that the two diagonals bisect each other at angle 90 degrees. Note: to bisect means to divide into 2 equal lengths.
So,
DK = 1/2 of DF.
Hence, the correct answer is divide DF by 2 to get length DK.
