A circle's center is at (3 ,4 ) and it passes through (3 ,2 ). What is the length of an arc covering ( pi ) /6 radians on the circle?

1 Answer
Feb 15, 2016

We need to find the radius of the circle and use it to calculate a fraction of the circumference. The distance is (2pi)/6 units.

Explanation:

First find the radius: we know the location of the center and of one point on the edge, so the radius is simply the distance between those points:

r=sqrt((x_2-x_1)^2+(y_2-y_1)^2) = sqrt((3-3)^2+(2-4)^2)=2 units

The circumference of the whole circle, which is 2pi radians, is 2*pi*r=4pi units. We want a fraction of that:

(pi/6)/(2pi)*4pi = (2pi)/6