Find an equation of the circle that satisfies the given conditions.
endpoints of a diameter are p(-1, 1) and q(5,9)

The equation of a circle:

(h,k) - the coordinates of the centre
r - the radius

The midpoint of the diameter is the centre of a circle.
The coordinates of the midpoint:

(x₁,y₁), (x₂,y₂) - the coordinates of endpoints



The centre of the circle is (2,5).

The radius is the distance between an endpoint of the diameter and the centre.
The formula for distance:




The radius is 5.