Answer
a) The car turned around in a complete circle
b) The government took the opposite view.
Work Step by Step
a) Since 360$^{\circ}$ is equal to a complete circle this means that the car turned in a complete circle
b) If one was to turn 180$^{\circ}$ they would find themselves facing in the opposite direction than they previously were. This phrase can be used to describe any similar turnaround.