  We present recent measurements of the unitarity triangle angle phi2(alpha)
using B -> pi pi, B -> rho rho, and B -> rho pi decays. The measurements are
based on data samples collected with the Belle and BaBar detectors at the KEKB
and PEP-II e+e- colliders, respectively. We also report on a new measurement of
a CP-violating asymmetry in B -> a_1+ pi- decay which will allow to constrain
further the angle phi2.
