# Alternative to remember area and circumference of a circle

Many people can actually remember either:

pir^2 or 2pir

But need a nudge to remind them which is area and which is circumference.

## To remember which is which:

Just remember r^2  must be an area

And a single r must be a line

So

\pir^2  = Area

2\pir  = The line of the circumference