Question

The point (7,2) lies on a circle. What is the length of

the radius of the circle if the center is located at
(2,1)?

Answer 1

• 
  `√(26) \ or\ 5.1\ units`

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Radius is the distance between the center and the point on the circle.

Use distance formula to find the radius:

• 
  `d=√((x_2-x_1)^2+(y_2-y_1)^2)`

Substitute r for d and given coordinates to get:

• 
  `r=√((7-2)^2+(2-1)^2) =√(25+1) =√(26) \ or\ 5.1\ units`