  Shocks are ubiquitous in astrophysical sources, many of which involve
relativistic bulk motions, leading to the formation of relativistic shocks.
Such relativistic shocks have so far been studied mainly in one dimension, for
simplicity, but the complex nature of the relevant astrophysical flows often
requires higher dimensional studies. Here we study the two-dimensional problem
of the reflection of a planer shock off of a wall for a general incidence angle
and a cold unshocked medium. We use primarily relativistic hydrodynamic
numerical simulations, and elaborately compare the results to an analytic
treatment. The simulations are performed both in the rest frame S of the
unshocked fluid, where the dimensionless proper speed of the singly shocked
fluid is $u_1=\Gamma_1\beta_1$ and the shock incidence angle is $\alpha_1$, and
in the rest frame S$^\prime$ of the point P of intersection of the incident
shock and the wall for regular reflection (RR). Good agreement is obtained
between the simulations in these two frames and with the analytic solution. The
establishment of a steady flow in frame S$^\prime$ is explored, along with the
transition between the strong and weak shock RR solutions. The transition line
between RR and Mach reflection (MR) is studied numerically in the
$u_1$-$\alpha_1$ plane and found to coincide with the analytic detachment/sonic
line. The flow properties along the sonic line are investigated in detail
focusing on how they vary between the Newtonian and relativistic limits.
