A tangent line is always perpendicular to the radius that shares the point of tangency. In other words, where your tangent line touches the circle (at only one point), that line is perpendicular to the radius at that point.
Answer:

Step-by-step explanation:
The original questions is suppose an ant walks counterclockwise on a unit circle from the point (1,0) to the endpoint of the radius that forms an angle of 240 degrees with the positive horizontal axis.
To find the distance ant walked we find the arc length of the sector with central angle 240 degree and radius =1 (unit circle)
arc length of a sector =
arc length of a sector =
arc length of a sector =

It makes and obtuse right triangle.