Question

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?

Answer 1

You need to use the distance formula to find the radius of the circle.


`d = √((x_2 - x_1)^2 + (y_2-y_1)^2) \\ \\ d = √((3-3)^2 + (8-5)^2) \\ \\ d = √(0^2+3^2) \\ \\ d = √(9) = 3`

The radius is 3.

The circumference is
`2 \pi r`


`= 6\pi \\ \\ =18.8`