$$\int\limits_0^{10\pi } {\left| {\sin x} \right|dx} $$ is

$$\int\limits_0^2 {\left[ {{x^2}} \right]dx} $$ is

$$\int_{ - \pi }^\pi {{{2x\left( {1 + \sin x} \right)} \over {1 + {{\cos }^2}x}}} dx$$ is

The equation of a circle with origin as a center and passing through an equilateral triangle whose median is of length $$3$$$$a$$ is :