Circle a triangle whose base has the length of the circle's circumference and whose height equals the circle's radius, which comes to multiplied by the radius squared: Equivalently, denoting diameter by "d", that is, approximately 79% of the circumscribing square (whose side is of length "d"). The circle is the plane curve enclosing the maximum area for a given arc length. This relates the circle to a problem in the calculus of variations, namely the isoperimetric inequality. Equation of a circle<br> In an "x"–"y" Cartesian coordinate system, the circle with centre coordinates ("a", "b") and radius "r" is the set of
Straight from the Desk by Ian Dury and Chaz Jankel, except where indicated. Straight from the Desk Straight from the Desk is a live album by Ian Dury & the Blockheads recorded on 23 December 1978 at the Ilford Odeon, Ilford, East London. There is little information available about the album, other than what can be heard on the record. During the performance of "Billericay Dickie" the audience break the venue's floor, presumably in excitement causing Dury to warn the audience to mind the hole as an introduction to "Hit Me with Your Rhythm Stick" and mention it repeatedly later in the set. Dury