What are the coordinates of the terminal point determined t= 10pi/3?

we know that :

10*pi/3> convert to degrees> 10*180/3=600 degrees

600=360+240

240 degrees belong to the III quadrant  so

the x-coordinate is negative

the y-coordinate is negative  

240°=180°+60°

60 degrees is the angle to find the terminal point

let  ∅=60°

in the unit circle

r=1 units

x=-r*cos ∅> x=-cos 60> x=-(1/2)

y=-r*sin ∅> y=-sin 60> y=-(√3)/2

the point is ( -1/2 , -√3/2)

what is the rest of the question? ?