Final answer:
The information provided lacks context, and specific measurements for calculating the length of side b, which is typically done using geometric or vector principles. Additional details from the question's figure are needed to perform the necessary calculations.
Step-by-step explanation:
The student's question appears to be related to vectors and their properties, specifically regarding the calculation of the length of a side in a geometric representation such as a triangle or parallelogram applied to vector addition or subtraction. However, the provided information is insufficient for a direct calculation, as there is no specific diagram or detailed information on vector A and vector B, nor the figure they are referring to.
Usually, vector lengths and the lengths of sides in a geometric representation can be computed using the Pythagorean theorem or vector addition/subtraction formulas. For example, if vectors represent the sides of a triangle, one can use the Law of Cosines to find the missing side if the lengths of two sides and the included angle are known. Similarly, if vector addition is used to form a parallelogram, the diagonals can represent the sum or difference of those vectors, and their lengths can be calculated accordingly.
Without specific measurements of the vectors or sides mentioned, or a particular figure to reference, we cannot provide the length of side b. For an accurate response, more context and data points are necessary to perform the calculations.