The standard form is
(x-xo)² + (y-yo)² = r²
Where xo,yo is the center of the circumference
and r is the radius.
We find the distance between the points to determine the diameter
d=sqrt ((9-2)² + (4-4)²) = sqrt (49) = 7
The radius of the circumference is d/2 = 7/2 = 3.5
And we can see that those points are at the same coordinate y = 4
The center is given then by , x = (9+2)/2 = 5.5
y = (4+4)/2 = 4
The equation results
(x-5.5)² + (y-4)² = (3.5)²
