9514 1404 393
Answer:
(x -2)² +(y -4)² = 25
Explanation:
The area of a square is half the product of the diagonals, so that product is 50·2 = 100. This is the square of the diameter, so the square of the radius is 100/4 = 25. Then the circle equation is ...
(x -h)² +(y -k)² = r² . . . . . . . circle with center (h, k) and radius r
(x -2)² +(y -4)² = 25
_____
The attached figure has A, B, C, D located on grid points for convenience in creating the figure. These points seem to differ slightly from the supplied diagram. The dimensions are the same, even if the figure is slightly rotated.