In rectangle $WXYZ$WXYZ​ , cap w cap y is equal to 4 x minus 15$WY=4x-15$WY=4x−15​ and cap x cap z is equal to 3 x plus 8$XZ=3x+8$XZ=3x+8​ . Find the lengths of the diagonals of cap w cap x cap y cap z$WXYZ$WXYZ​ .