A circle has a center at (3, 5). The point (3, 8) is on the circle. What is the circumference of the circle to the nearest tenth of a unit?

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Answer 1 · 2016-11-10T20:06:38

#c = 18.8#

#(x - h)^2 + (y - k)^2 = r^2#

where #(x,y)# is any point on the circle, #(h,k)# is the center, and r is the radius.

Substitute the point and the center into the equation:

#(3 - 3)^2 + (8 - 5)^2 = r^2#

#(0)^2 + (3)^2 = r^2#

#r = 3#

The circumference, #c = 2pir#

#c = 18.8#