Question

A circle whose center is at (1,-3) passes through (7, 5). What is the length of the radius of the circle?

Answer 1

Radius: `color(green)(10)`

Explanation:

The radius is the distance from the center to any point on the circumference.

In this case (using the Pythagorean Theorem)
`color(white)("XXX")r=sqrt((7-1)^2+(5-(-3))^2)`

`color(white)("XXXX")=sqrt(36+64)`

`color(white)("XXXX")=10`