I need help answering this problem, more important understand how to solve it! Thanks in advance!

A delta strain rosette, attached to a structural metal link on a backhoe arm-assembly, measures the following strains:-

(a) Determine the strain components , and (assuming no strain normal to the rosette).

(b) Determine the principal strains and maximum shear strains at the rosette's location.

(c) Determine the principal stresses and the plane on which they occur. Take E = 200 GPa and v = 0.30.