- Face in the bricks
- Painting in the lobby
- Circinus
- Octans
If there is an underlying oneness of all things, it does not matter where we begin, whether with stars, or laws of supply and demand, or frogs, or Napoleon Bonaparte. One measures a circle, beginning anywhere.
Charles Fort, Lo! (1931)- Euler is credited for popularizing the Greek letter π (lowercase pi) to denote the ratio of a circle’s circumference to its diameter, as well as first using the notation f(x) for the value of a function, the letter i to express the imaginary unit √-1, the Greek letter Σ (capital sigma) to express summations, the Greek letter Δ (capital delta) for finite differences, and lowercase letters to represent the sides of a triangle while representing the angles as capital letters.
- Flag_of_Denver,_Colorado.svg (Wikimedia Commons)
- degree
- Circle (Wikipedia)
A circle is a shape consisting of all points in a plane that are at a given distance from a given point, the centre. The distance between any point of the circle and the centre is called the radius.
