Section 11.5 - Circles
Circles are going to be the last stop on our discussion of individual planar figures. In a way, they're the natural end point for polygons. If you take one and let the number of sides go to infinity (notice I specifically didn't say equal infinity) then you end up with what we commonly mean by a circle.
Videos
Lectures
So far, all of the shapes and objects we've talked about have been made from things that are straight. Circles, on the other hand, are the first curved shape we're going to discuss here including their definition, a formula for the circumference and an approximation method for finding a formula for the area. (lecture slides)
In this lecture, we're going to look at two classic examples of questions involving circles, their area and their circumference. (lecture slides)
Explorations
When does pi equal 3? I actually saw this question come up on a discussion board a while ago and I’m honestly not sure whether the person who posted it was being serious or not. The answer is both never and when it's convenient.
