standard_description: Derive the equation of a circle of given center and radius using the Pythagorean Theorem; complete the square to find the center and radius of a circle given by an equation.
problem_activity: Task
Is there an equilateral triangle $ABC$ so that  $\overline{AB}$ lies on the $x$-axis and $A$, $B$, and $C$ all have integer $x$ and $y$ coordinates?  Explain.


aligns: no