Au clair de la lune Au clair de la lune "" (, lit. "By the Light of the Moon") is a French folk song of the 18th century. Its composer and lyricist are unknown. Its simple melody () is commonly taught to beginners learning an instrument. Some sources report that "plume" (pen) was originally "lume" (an old word for "light" or "lamp"). 19th-century French composer Camille Saint-Saëns quoted the first few notes of the tune in the section "The Fossils", part of his suite "The Carnival of the Animals". Claude Debussy, composer of the similarly named "Clair de lune" from his "Suite bergamasque", uses "Au
Lune of Hippocrates give the only constructible squarable lunes; in particular, there are no constructible squarable convex lunes. Lune of Hippocrates In geometry, the lune of Hippocrates, named after Hippocrates of Chios, is a lune bounded by arcs of two circles, the smaller of which has as its diameter a chord spanning a right angle on the larger circle. Equivalently, it is a non-convex plane region bounded by one 180-degree circular arc and one 90-degree circular arc. It is the first curved figure to have its exact area calculated mathematically. Hippocrates wanted to solve the classic problem of squaring the circle, i.e. constructing