So I'm stuck on this question. So I was told to find the midpoint of (3,-4) and (-2,8). I did the math and I ended up getting (.5,2). Now it's the next question states, "If the point you found is the center of a circle, and the other two points are points on the circle, find the length of the radius of the circle. (That is, find the distance between the center point you found and one of the other two points given) Find the exact answer and simplify as much as possible. Show Work"

I'm having quite a bit of trouble finding the length of the radius