The jet energy loss, modification of jet shape, and jet-acoplanarity are consequences of jet-quenching in heavy-ion collisions. The comparison of intra-jet broadening in p+p and heavy-ion collisions provides a way to disentangle the vacuum shower and medium-induced gluon radiations. On the other hand, the measurement of jet acoplanarity in the QGP promises to provide unique and incisive insight into the physics of jet-medium interaction and the quasi-particle nature of the QGP. In this seminar, I will discuss the first observations of intra-jet broadening and medium-induced acoplanarity using semi-inclusive direct photon+jet and hadron+jet measurements in Au+Au and p+p collisions at a center of mass energy of 200 GeV. I will also shed light on STAR's data-taking plan for the high statistics measurements with extended kinematic coverage.