circle wiki:
>This article is about the shape and mathematical concept of circle; for other meanings, see Circle (disambiguation). In Euclidean geometry, a circle is the set of all points at a fixed distance, called the radius, from a fixed point, called the centre (center). The points can only be those that are part of a conic section; within the set of a plane bisecting a cone. Circles are simple closed curves, dividing the plane into an interior and exterior. Sometimes the word circle is used to mean the interior, with the circle itself called the circumference. Usually however, the circumference means the length of the circle, and the interior of the circle is called a disk or disc.
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blue wiki:
>For other uses, see Blue (disambiguation) Blue is one of the three primary additive colors; blue light has the shortest wavelength range (about 420-490 nanometers) of the three additive primary colors. The English language commonly uses "blue" to refer to any color from blue to cyan.An example of a blue color in the RGB color space has intensities [0, 0, 255] on a 0 to 255 scale. Blue is the complement of yellow. For this reason, blue 80A filters are used to correct for the excessive redness of tungsten lighting in color photography.Many languages do not have separate terms for blue and green, and in the Swedish language, blå, the modern word for blue, was used to describe black until the early 20th century. The modern English word blue comes from the Middle English, where it began to be used along with bleu, an Old French word of Germanic origin (possibly Old High German blao, "shining"). A Scots and Scottish English word for "blue" is blae, from the Middle English bla ("dark blue", from the Old English blæd).
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