equal angles
31Exact sciences (The) in Hellenistic times: texts and issues — The exact sciences in Hellenistic times: Texts and issues1 Alan C.Bowen Modern scholars often rely on the history of Greco Latin science2 as a backdrop and support for interpreting past philosophical thought. Their warrant is the practice… …
32Newton's theorem of revolving orbits — Figure 1: An attractive force F(r) causes the blue planet to move on the cyan circle. The green planet moves three times faster and thus requires a stronger centripetal force, which is supplied by adding an attractive inverse cube force. The …
33Gear — For the gear like device used to drive a roller chain, see Sprocket. This article is about mechanical gears. For other uses, see Gear (disambiguation). Two meshing gears transmitting rotational motion. Note that the smaller gear is rotating… …
34Rotation matrix — In linear algebra, a rotation matrix is a matrix that is used to perform a rotation in Euclidean space. For example the matrix rotates points in the xy Cartesian plane counterclockwise through an angle θ about the origin of the Cartesian… …
35Diffraction grating — A very large reflecting diffraction grating. In optics, a diffraction grating is an optical component with a periodic structure, which splits and diffracts light into several beams travelling in different directions. The directions of these beams …
36Similarity (geometry) — Geometry = Two geometrical objects are called similar if one is congruent to the result of a uniform scaling (enlarging or shrinking) of the other. One can be obtained from the other by uniformly stretching , possibly with additional rotation,… …
37Sundial — A sundial is a device that measures time by the position of the Sun. In common designs such as the horizontal sundial, the sun casts a shadow from its style (a thin rod or a sharp, straight edge) onto a flat surface marked with lines indicating… …
38Bisection — In geometry, bisection is the division of something into two equal or congruent parts, usually by a line, which is then called a bisector . The most often considered types of bisectors are segment bisectors and angle bisectors .A segment bisector …
39Spherical trigonometry — Spherical triangle Spherical trigonometry is a branch of spherical geometry which deals with polygons (especially triangles) on the sphere and the relationships between the sides and the angles. This is of great importance for calculations in… …
40Hyperbola — This article is about a geometrical curve, a conic section. For the term used in rhetoric, see Hyperbole …
