Anyone out there please help me with this question. I've been struggling with it for long. Thanks in advance.

The figure below represents part of a transverse wave at a particular instant, traveling along a string with a speed of 50m/s in the direction of x

a) What is the wavelength of the wave?
b) What is the amplitude of the wave particle?
c) Calculate the period of oscillation of the string
d) What is the frequency of the wave particle?​