Standard Form of a Circle

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

The center of a circle given by the equation $$(x-h)^2 + (y-k)^2 = r^2$$ is (h, k).

The radius of a circle given by the equation $$(x-h)^2 + (y-k)^2 = r^2$$ is r, which is the square root of the right side of the equation.

The diameter of a circle is twice the radius, given by the formula $$d = 2r$$ .

The area of a circle is calculated using the formula $$A = \text{π}r^2$$ .

The diameter is $$2\text{√}135$$ .

The center is (2, -3).

The radius is 3.

To convert the area to a numerical value, substitute the radius into the area formula $$A = \text{π}r^2$$ and calculate.

The area increases with the square of the radius; if the radius doubles, the area increases by a factor of four.