  The $\Lambda$CDM model of structure formation makes strong predictions on
concentration and shape of DM (dark matter) halos, which are determined by mass
accretion processes. Comparison between predicted shapes and observations
provides a geometric test of the $\Lambda$CDM model. Accurate and precise
measurements needs a full three-dimensional analysis of the cluster mass
distribution. We accomplish this with a multi-probe 3D analysis of the X-ray
regular CLASH (Cluster Lensing And Supernova survey with Hubble) clusters
combining strong and weak lensing, X-ray photometry and spectroscopy, and the
Sunyaev-Zel'dovich effect. The cluster shapes and concentrations are consistent
with $\Lambda$CDM predictions. The CLASH clusters are randomly oriented, as
expected given the sample selection criteria. Shapes agree with numerical
results for DM-only halos, which hints at baryonic physics being not so
effective in making halos rounder.
