Question

the point 3,2 lies on a circle.what is the exact length of the radius of this circle if the center is located at (-1,-4)

Answer 1

You can use the distance formula to solve this.

Distance Formula:

`d = √((X_2 -X_1)^2 + (Y_2 - Y_1)^2)`

I am going to use point (3,2) as point 1 and (-1,-4) as point 2
Insert the points into the formula

`d = √((X_2 -X_1)^2 + (Y_2 - Y_1)^2)`

`d = √(((-1) - 3)^2 + ((-4) - 2)^2)`
Solve:

`d = √(((-1) - 3)^2 + ((-4) - 2)^2)`

`d = √((-4)^2 + (-6)^2)`

`d = √(16 + 36)`

`d = √(52)`

`d = √(52) = √(4)√(13)`

`d = √(52) = 2 √(13)`

`d = 2 √(13)`

`radius = 2 √(13) = 7.2111`