Compute all parts of given problem:
Problem: An energetic photon of wavelength 3.1 pm scatters off an electron at rest at an angle of 123 degrees.
Part A: What is the wavelength of the scatter photon?
Part B: What is the longest wavelength possible?
Part C: For what angle scattering does the scattered photon reach the maximum wavelength?
Please show step to find the wavelength of the scatter photon.