A circle's center is at (4 ,6 )(4,6) and it passes through (3 ,1 )(3,1). What is the length of an arc covering (pi ) /3 π3 radians on the circle?

1 Answer
Feb 8, 2016

The arc length is sqrt(26)/3 pi263π.

Explanation:

First of all, you need to compute the radius.

If you center is at (4, 6)(4,6) and an arbitrary point on a circle is (3,1)(3,1), we can compute the radius as follows:

r = sqrt((4-3)^2 + (6-1)^2) = sqrt(1 + 25) = sqrt(26)r=(43)2+(61)2=1+25=26

Now, the the length of an arc covering the whole circle would be equivalent to the perimeter of a circle, 2pi r2πr.

In your case, you would like to compute an arc covering pi/3π3 radians instead of the whole 2pi2π (equivalent to 60^@60 which is 1/616 of the whole circle).

Thus, your arc length is pi/3 r = sqrt(26)/3 piπ3r=263π.