Pi and the circumference of a circle

Pi is the ratio of the circumference of a circle to its diameter, or π = C/d. From this formula we then get the formula C = πd.

I go through practice problems where we calculate the circumference, given either the diameter or the radius, and then a problem where we are asked the radius, given the circumference. Lastly, we look at at real-life problem that involves the length of a path in a garden.

See also

How to calculate the area of a circle, plus simple proof for the formula — video lesson

Math Mammoth Geometry 2 — a self-teaching worktext with explanations & exercises (grades 4-5)

Back to the geometry videos index

Back to pre-algebra videos index

Back to all videos index