1) All interior angles of a square are right angles, so angle WER measures 90°
2) All squares are parallelograms, and diagonals of a parallelogram bisect each other, meaning PA=AE=8 cm. Thus, PE=16 cm
3) All squares are rectangles, and diagonals of a rectangle are congruent, meaning WR=16 cm. Then, using the fact that the diagonals bisect each other, we get that WA=8 cm
4) If we consider right triangle WPR, we know it is isoceles because all sides of a square are congruent. So, the length of WP is: