Answer:
Radius = 5 units
Explanation:
We can use the formula of getting magnitude of a line joining two points;
(x1, y1) and (x2, y2)
Length = √((x2-x1)² + (y2-y1)²)
Therefore;
In this case the radius will be; PC
Length of PC = √((3-7)² + (-2-1)²)
= √((-4)² + (-3)²)
= √(16 +9)
= √ 25
= 5 units
Thus the radius is 5 units