The point (-1,2) is on the circle whose center is (4,1). what is the radius?

(4,1)  (-1, 2)
Distance = Square Root ( (X difference)^2 + (Y difference)^2 )

Distance = Square Root ((5^2) + (1 -2)^2)
Distance = Square Root ((25) + (-1^2))
Distance = Square Root  (25 +1)
Distance = Square Root  26
Radius = 5.0990195136

1. 3/6 or 1/22. 1/123. 1/84. 1/105. 2/12 or 1/6

The answer to your question is b