Solve the each part of following problem given below:
Problem: A photon of initial energy 0.10 MeV undergoes Compton scattering. After scattering, the photon's energy is 0.09 MeV.
Part A: Find the scattering angle for the photon.
Part B: Find the recoil energy of the electron.
I need help to determine the scattering angle for the photon and the recoil energy of the electron.