Answer: the length of the base is 15 kilometers.
Step-by-step explanation:
formula : Area of parrallelogram = Length of base x height
Given: Area of parallelogram = 300 square kilometers
height = 20 kilometers
Substituting values in the formula , we get
300 = Length of base x 20
Length of base =
= 15 kilometers
Hence, the length of the base is 15 kilometers.