Time is a flat circle, Matthew McConaughey tells us, neglecting to explain how then we could measure time's circumference to derive its diameter, using pi. (Maybe it's best not to take the sentiment ...

Pi equals the ratio of a circle's circumference to its diameter, or approximately 3.14. Pi is infinite, meaning its exact value is incalculable, but in 2015 Rajveer Meena recited 70,000 decimal places ...

When working with circles it is important to recognise and be able to name different parts of the circle. A segment of a circle is an area enclosed by a chord and an arc. What is the name given to a ...