Matrices and linear transformations

Identify the following matrices as reflections, shears, scalings,rotation or projections for the unit square.

a)$\displaystyle \left(\begin{array}{cc}1/5&2/5\\2/5&4/5\end{array}\right)$

b)$\displaystyle \left(\begin{array}{cc}1/2&\sqrt3/2\\-\sqrt3/2&1/2\end{array}\right)$

I thought that b was a straightforward rotation using the rotation matrix :

$\displaystyle \left(\begin{array}{cc}cos\theta&sin\theta\\-sin\theta&cos\theta\end{array}\right)$

where the angle is 60 degrees, but when i graphed the unit square under this transformation it doesnt look like a simple rotation.

Part a i am totally stuck on.