Answer:
<h2>The radius is 4 units long.</h2>Step-by-step explanation:
The given equation is
This equation belongs to a circle, which center is at (0.5, 3.5) and its radius is 4.
You can deduct its elements, becase this equation of the circle is explicit, which means the constant term represents the square power of the radius. Solving that, we have
Therefore, the radius is 4 units long.