# Definition:Archimedean Spiral

## Definition

The Archimedean spiral is the locus of the equation expressed in Polar coordinates as:

$r = a \theta$

### Archimedes' Definition

If a straight line of which one extremity remains fixed be made to revolve at a uniform rate in a plane until it returns to the position from which it started, and if, at the same time as the straight line revolves, a point moves at a uniform rate along the straight line, starting from the fixed extremity, the point will describe a spiral in the plane.

## Also known as

Some sources render this as a spiral of Archimedes.

## Also see

• Results about Archimedean spirals can be found here.

## Source of Name

This entry was named for Archimedes of Syracuse.