Solving for G and \epsilon Given E, v, and \sigma

[xrayzulu]

I am given E= 210 GPa v=0.3

\sigma= [ -20 15 ]
15 30

How do I find G = ?

and \epsilon

Any help much appreciated.

 

[Mapes]

Hi xrayzulu, welcome to PF. Please show your attempt first; that's what the template is there for.