Question

The point (-3,3) lies on a circle. What is the length of the radius of this circle if the center is located at (10,6) ?

Answer 1

You should find distance between two points
A(x1, y1) and B(x2, y2)

Answer 2

The radius is from center to point on a circle.
So your task is count distance between two points: S(10,6) and A(-3,3).
Distance between two points A(x1, y1) and B(x2, y2) count from this formula:

`|AB|=√((x_2-x_1)^2+(y_2-y_1)^2) \\ \\ \hbox{So:} \\ \\ r=|SA|=√((-3-10)^2+(3-6)^2)=√((-13)^2+(-3)^2)=√(169+9)= \\ r= √(178)`