My older sister said I got this problem wrong but I don't understand her explanation.

Question

In Italy, there is a large circular test track that is used to test race cars and other high-speed automobiles.

 

a. Suppose a similar track has a radius of 6 kilometers. Find the circumference of the track. 

 

b. While test driving a new car on the similar track, a driver starts at the right-hand side of the circular track, travels in a counter-clockwise direction, and stops 3/5 of the way around the track. Using the center of the track as the origin and the starting point as the intersection of the x-axis and the circle represented by the track, find the coordinates, to the nearest tenth, of the point where the driver stopped the car. 

Answer 1

a.

C = 2πr, C = 2π6, C = 12π

 

b.

3/5 of the way is 3/5 of 360°.

216°

sin 216° ≈ -0.0587785252

-0.0587785252 = y / 6

-3.526 = y

 

Do the same for cos to find the x-coordinate