Rearranging gives (x - 5)² + (y + 3)² = 9, so the radius is √9 = 3.

Using the formula for the radius of the incircle r = A/s, where A is the area and s is the semi-perimeter.

Using the formula for the radius of the incircle r = A/s, where A is the area and s is the semi-perimeter.

The center of the circle is (4, 3) since it is 3 units above the tangent point (4, 0).

Using the distance formula, the radius can be calculated from the center found using the circumcircle method.

Circumference C = πd = π(10) = 10π.

Rearranging the equation to standard form gives (x - 2)² + (y + 3)² = 0, thus the center is (2, -3).

The radius is the distance from the center to the point, which is √(3² + 4²) = √25 = 5.

The radius is 5 (distance from (0,0) to (3,4)), so the equation is x² + y² = 5² = 25.

The area of a circle is given by A = πr², so A = π(10)² = 100π.

The area of a circle is given by A = πr², so A = π(7)² = 49π.

The distance between centers (1, 2) and (-3, -4) is calculated using the distance formula.

Using the standard form, the equation is (x + 1)² + (y - 2)² = 4² = 16.

The standard form of a circle's equation is (x - h)² + (y - k)² = r², where (h, k) is the center and r is the radius.

The diameter is twice the radius, so 2 * 7 = 14.

The radius is √16 = 4, so the diameter is 2 * radius = 8.

The radius is the square root of 16, which is 4.