Help with Unit Circle Problem

My question reads

"Suppose t is the length of the arc on the unit circle whose initial point is (1,0), and terminal point is P (x,y). If t=3.5, sketch on the unit circle below the approximate location of P(x,y)"

Okay, I understand this part of the question, I know the point is in quadrant 3, etc.

Then the question asks "find the x-coordinate and y-coordinate of P accurate to two decimal places"

I have the answers, but I am dumbfounded as to how they were acquired.

(.-94, .-35) are the coordinates.

Any help would be much appreciated.

Thank you