Answer:
P1 (6, 2/3 π)
P2 (6, 10/3 π)
P3 (6, 14/3 π)
Step-by-step explanation:
To find the other three points you take into account that if you sum 2π to one coordinate you have the same point.
Hence, by adding 2π to -4π/3, and again other two times:
[tex]-\frac{4}{3}\pi+2\pi=\frac{2}{3}\pi\\\\\frac{2}{3}\pi+2\pi=\frac{8}{3}\pi[/tex]
[tex]\frac{8}{3}\pi+2\pi=\frac{14}{3}\pi[/tex]
hence, the other two points are
P1 (6, 2/3 π)
P2 (6, 10/3 π)
P3 (6, 14/3 π)