A circle's center is at (3 ,9 ) and it passes through (5 ,8 ). What is the length of an arc covering (7pi ) /4 radians on the circle?

2 Answers
Jan 28, 2016

( 7 sqrt(5) pi ) / 4

Explanation:

Please check my solution here for a detailed explanation.

Solution
Radius r = sqrt( (5 - 3)^2 + (8 - 9)^2 ) = sqrt(5) .
Arc length S = ( 7 sqrt(5) pi ) / 4 .

Jan 28, 2016

( 7 sqrt(5) pi ) / 4