Solution: Because the garden is tangent to the two coordinate axes, the distance from the garden center to the two coordinate axes is equal, so the coordinate of the garden center can be set to (m, m);
The circle passes the point (4, 1), so there is the equation m? =(m-4)? +(m- 1)? , expand and simplify to get m? - 10m+ 17 = 0; So I have to:
m =( 10√32)/2 = 5 ^ 2√2; Get a c? (5-2√2,5-2√2); c? (5+2√2,5+2√2);
So, c? c? √ {2 [(5+2 √ 2)-(5-2 √ 2)]? =√64=8.