$\"\"$

The polar equation is $\"\"$ .

Transform the equation to rectanglular coordinates :

$\"\"$

Multiply on each side by $\"\"$ .

$\"\"$ .

Substitute $\"r$ and $\"\"$ .

$\"\"$

$\"\"$ .

The equation $\"\"$ is in the form of standard circle equation $\"\"$ with center $\"\"$ and radius $\"\"$ . $\"\"$

The polar equation is $\"\"$ , $\"\"$ is a circle with radius $\"\"$ and center $\"\"$ in rectangular coordinates.