Circular segment Circular segment In geometry, a circular segment (symbol: ⌓) is a region of a circle which is "cut off" from the rest of the circle by a secant or a chord. More formally, a circular segment is a region of two-dimensional space that is bounded by an arc (of less than 180°) of a circle and by the chord connecting the endpoints of the arc. Let "R" be the radius of the circle, "θ" the central angle in radians, α is the central angle in degrees, "c" the chord length, "s" the arc length, "h" the sagitta (height) of the
Schema for vertical declining dials graphical techniques were used to derive formula_1 and formula_2 and from it formula_3. There are four basic angles that are needed to construct a vertical declining dial, Waugh described them such: The four basic calculation have a certain symmetry. At this point only three lines matter, the vertical, the substyle length and substyle height. A circle marked off in 15° angles is needed (circular protractor). Before the protractor became ubiquitous, compasses and the Scale of Chords were used for laying out an angle. This method originally used them. At this point only three lines matter, the vertical, the substyle length