Question

What is the circumference of the circle whose equation is (x-9)^2+(y-3)^2=64?

Answer 1

a) 16pi b)4pi c)8pi d)64pi

Answer 2

radius is 8
circumference is 2*r*pi

Answer 3

what is the answer?

Answer 4

See the basic equation of a circle with radius 'r' is x^2 + y^2 = r^2
And this is a modification of it (x-a)^2 + (y-b)^2 = r^2 but the radius of circle 'r' is still the same. In a way the circle is just moved, with (a,b) being new centre points(Previously they were 0,0).
Anyway, the circumference of a circle = 2pi(r)
There for here (x-9)^2+(y-3)^2=64= 8^2, r=8
So circumference = 2pi(8)= 16pi
Got it?

Answer 5

I e what is 2*8

Answer 6

so 16pi is right?

Answer 7

yeah, it is.

Answer 8

thanks all

Answer 9

you got what i said?

Answer 10

yes =)

Answer 11

Good. :)