Point A is the midpoint of one of the sides of a square. On the side opposite this spot, two in-phase loudspeakers are located at adjacent corners, as in Figure 27.39. Standing at point A you hear a loud sound because of constructive interference among the identical sound waves coming from the speakers. As you walk along the side of the square toward either empty corner, the loudness diminishes slowly to nothing and then increases again until you hear a maximally loud sound at the corner. If the length of all side of the square is 2.9 m, discover the wavelength of the sound waves.