A circle has a center at (1 ,3 ) and passes through (2 ,1 ). What is the length of an arc covering pi /4 radians on the circle?
1 Answer
Mar 11, 2016
≈ 1.756 units
Explanation:
To calculate length of arc , the radius is required. This can be found using the 2 points given and the
color(blue)" distance formula "
d = sqrt((x_2-x_1)^2 + (y_2-y_1)^2) where
(x_1,y_1)" and "(x_2,y_2)" are 2 coordinate points " let
(x_1,y_1)= (1,3)" and "(x_2,y_2)=(2,1) radius (r )
=sqrt((2-1)^2 + (1-3)^2) = sqrt5 length of arc =
2pir xx "fraction of circle covered "
= cancel(2pi)xxsqrt5 xx (pi/4)/cancel(2pi) = sqrt5xxpi/4 ≈ 1.756