A circle's center is at (8 ,1 ) and it passes through (2 ,5 ). What is the length of an arc covering (5 pi ) /6 radians on the circle?

1 Answer
Jun 25, 2018

(8,1) and (2,5)

d^2=(8-2)^2+(1-5)^2

d^2=36+16

d=sqrt 52

The distance between the points is sqrt53 so the radius of the circle is sqrt52

Length of an arc is theta/360xxpiD

Where theta is the angle of the arc and D is the diameter of the circle.

[5pi]/6=150^@

Length=150/360xxpixx2sqrt52

Length is 18.87862233