Identify Geometry and Given Values: Identify the geometry of the problem and the given values. ABCD is a square with side length 2, so BC=2. Since Q is the midpoint of BC, BQ=QC=1.
Recognize Angle Configuration: Recognize that ∠APD=135∘ suggests P is located such that it forms an obtuse angle with points A and D. This configuration maximizes the distance PQ when P is on the circle centered at D with radius DA, passing through A.
Calculate Circle Radius: Calculate the radius of the circle. Since DA is a diagonal of the square, DA=22+22=8=22.
Determine Position for Maximum PQ: Determine the position of P for maximum PQ. When P is on the extension of line AD, at a distance of 22 from D, PQ will be maximized because it is the hypotenuse of triangle PQD.
Calculate PQ Using Pythagorean Theorem: Calculate PQ using the Pythagorean theorem in triangle PQD, where PD=22 (radius) and DQ=1 (half of BC). PQ2=PD2+DQ2=(22)2+12=8+1=9.