Final answer:
Without additional information or assumptions about the lengths of the other sides of the pentagon, we cannot determine the length of side PQ in a pentagon with a perimeter of 65 units.
Step-by-step explanation:
To find the length of side PQ in the polygon (a pentagon in this case), we can use the formula for the perimeter of a polygon, which is the sum of the lengths of all its sides. Since the problem states that the perimeter is 65 units, we know the sum of all the sides equals 65. If we let PQ be the unknown side we are solving for and assume the other sides are known or represented by expressions given in the question, we could set up an equation to solve for PQ.
However, the question doesn't provide enough information to solve for PQ without making assumptions about the other sides. In problems like this, additional information about the specific lengths of the other sides or information that multiple sides are congruent would be necessary. Without this, or a representation such as a diagram, we cannot conclusively answer which of the given options (a) 10 units, (b) 15 units, (c) 20 units, or (d) 25 units represents the length of side PQ.