Answer:Certainly! To determine the length of the base of the parallelogram, we need to clarify which of the given measurements (13 cm, 12 cm, or 20 cm) refers to the base. Typically, in a problem like this, the base is one of the given dimensions, and the other measurements might relate to other sides or heights. If you are asking for the length of a specific side labeled as the base, please specify which measurement corresponds to it. If these measurements are all sides or related to other parts of the parallelogram, additional information such as angles or height would be necessary to calculate the base length. Please provide more details so I can assist you accurately.Step-by-step explanation: