SOLUTION: A circle whose center is at the point (1,2) passes through the point (4,-2). What is the length of the radius of the circle?

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Question 77245: A circle whose center is at the point (1,2) passes through the point (4,-2). What is the length of the radius of the circle?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Since we know the point at the center and the point at the edge, we can use the distance formula to find the radius:
Solved by pluggable solver: Distance between two points in two dimensions
The distance (denoted by d) between two points in two dimensions is given by the following formula:

d=sqrt%28%28x1-x2%29%5E2+%2B+%28y1-y2%29%5E2%29

Thus in our case, the required distance is
d=sqrt%28%281-4%29%5E2+%2B+%282--2%29%5E2%29=+5+


For more on this concept, refer to Distance formula.


Since the distance is 5, the radius is 5 units.