Circle Review

Circles are a subset of ellipses, so we will take a look at them a little bit. However, you should have already learned about circles in a previous class, so we will just review the basic concepts and then look at a few examples of circles as conic sections.

A circle is a curve formed by all points that are an equal distance called the radius from a fixed point called the center. The standard equation of a circle having center \((h,k)\) and radius \(r\) is given below.

\[(x-h)^2 + (y-k)^2 = r^2\] Graph of a circle centered at the point (h,k) and having radius r.

Let's look at a few examples.

Ellipses

Circle Review