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
There Is a Light That Never Goes Out a single release by WEA to promote the "...Best II" compilation. The song reached number 25 on the UK Singles Chart, making it their last UK Top 40 appearance to date. Music critics consider "There Is a Light That Never Goes Out" to be one of the Smiths' finest efforts. Simon Goddard wrote, "In a straw poll among Smiths fans today, 'There Is a Light That Never Goes Out' would more than likely still come out victorious", which he credits to the "perfect balance" of Marr's compositional skills and Morrissey's lyricism. AllMusic's Tim DiGravina calls it "a standout among standouts