Answer:
(2, 2/3 * pi)
Explanation:
( -1, sqrt(3))
to find the radius
sqrt(x^2 + y^2) = r
sqrt( (-1)^2 + (sqrt3)^2) = r
sqrt(1+3) =r
sqrt(4) =r
2=r
to find theta
theta = arctan (sqrt(3)/-1)
theta = -60 degrees
you need theta between 90 and 180
add 180 to theta
theta = 120
you need theta in radians
120 * pi/180 = 2/3 * pi