Compute the right answer of the following problem

Problem- Ocean waves with amplitude of 2.0 m and a wavelength of 15 m go through a 55-m opening m a breakwater that is shaped like a line and protects a body of water shaped like a square 800 m on a side between the breakwater, the beach, and two rocky ridges on either side.

Part 1- Draw a sketch of this situation that accurately and quantitatively illustrates the angle through which the waves are diffracted. (Also show your work in computing that angle.)

Part 2- Indicate some points on your sketch where boats within the breakwater will feel little wave motion.

I want help to specify some points on sketch where boats within the breakwater.