Homework #7
Reminder  you're going to need these webpages:
http://www.continuummechanics.org/techforms/index.html
to do this homework.... unless
you prefer to use Matlab, Mathematica, etc.

Figure out the deformation gradient at the center of the square element.

Figure out the deformation gradient in the triangle element below.

How many degrees of rigid body rotation is the triangle element experiencing?
That's all.