Today, they say, is Look for Circles Day. The idea of the day, aimed mostly at entertaining the young ‘uns, is to see how many circles you can spot. We come across hundreds of circles each day, so in addition to the obvious ones, try to look for circles in unexpected places, and even look for implied circles (where objects occur, or are placed, in such a way that they form a circle).

Look for Circles Day is a great opportunity to entertain kids of all ages with one of the most interesting shapes in nature, and to teach them some maths and geometry in the process. Here are some interesting circle facts:

A circle is an infinite set of points on a plane that are all the same distance from a specific, predefined point.

Of all shapes with a given perimeter, the circle has the largest area. Or to put it another way, circles have the minimum possible perimeter for a given area.

They are the only single-sided shape with an area.

A circle with an infinitely large radius is a straight line (there’s a hint to give you the upper hand when searching for circles!)

A circle can be split in two identical halves in an infinite number of ways, or stated more formally, a circle has an infinite number of lines of symmetry.

The circumference and perimeter of a circle are related through the mathematical constant pi, or π – a very interesting number in itself, as we discussed previously.

A solid circle is a wheel, and we all know what useful invention the wheel was!

Apparently, according to research done by the Max Planck Institute for Biological Cybernetics in Tübingen, when we have no way to navigate – for example in a thick fog, or a moonless night – we tend to walk in circles (literally).

There is a form of divination called ‘gyromancy’ where people are made to walk in a circle until they fall down from dizziness, and the location where they fell is then used to predict future events.

Yep, as I said – circles are amazing things… Happy circle spotting!

Too cool, Gerry. I’m having a hard time with the infinitely large radius, though! But I guess, that’s what infinity is – hard to wrap our brains around it.

Too cool, Gerry. I’m having a hard time with the infinitely large radius, though! But I guess, that’s what infinity is – hard to wrap our brains around it.

Thanks much, Sid! Did you do some circle-spotting with the girls?