this is my take home test and i have no idea.... help?

Scenario: you are sitting in a movie theater that has three speakers on each side emitting the same sound frequency (1200 HZ). the sitting area is 20 meters by 20meter square with each seat area 2 meters by 2meters. the speakers are placed at ear level 5 meters apart at 5 meters,10meters, and 15 meters on each side.

Problems:

1.determine the wavelength of the sound emitted by each speaker.

2. Find one place of constructive interference between all three speakers coming from one side. (hint: there may be more than one answer)

3.Find one place of constructive interference between all three speakers on the other side.

4. estimate based on your data where the best seat in the house is out of 100 seats given. use your answers from parts 2 and 3

............ ha ha yeah i find it reeeeeeeaaaaaaaaalllllllllyyyyyyyyyy hard....

so anyone wanna help?