A central angle is an angle whose vertex is at the center of a circle, and whose sides (rays) extend to the circumference of the circle. The central angle is formed between two radii of the circle that connect the center of the circle to two points on its edge. Central angles are important in various mathematical and geometric contexts, particularly in relation to the properties of circles, such as arc length and sector area.
Bisection is a mathematical method used to find roots of a continuous function. It is a type of bracketing method, which means it narrows down the search for a root within a certain interval. The key idea behind the bisection method is to divide an interval in half and, based on the signs of the function at the endpoints, determine which half contains the root.
Birkhoff's axioms refer to a set of axioms introduced by mathematician George David Birkhoff in the context of defining the concept of a "relation" in mathematics, particularly pertaining to the fields of algebra and geometry. However, it is important to clarify that Birkhoff is perhaps best known for his work in lattice theory and the foundations of geometry.
A bicone is a geometric shape that resembles two cones joined at their bases. It resembles a double-cone structure and is commonly found in various contexts, including mathematics, geometry, and design. The shape can be characterized by its symmetrical properties and a specific relationship between its height and the radius of its circular base. In computer graphics and 3D modeling, biconic shapes are often used to represent certain types of objects or to create complex designs.
A bicentric polygon is a type of polygon that possesses both a circumcircle and an incircle. A circumcircle is a circle that passes through all the vertices of the polygon, while an incircle is a circle that is tangent to each side of the polygon. For a polygon to be classified as bicentric, it must meet specific criteria: 1. **Circumcircle**: All the vertices of the polygon lie on a single circle.
The Bankoff circle is a concept in the field of mathematics, specifically in geometry. It is associated with the study of triangles and their properties. More precisely, the Bankoff circle is defined in relation to a triangle and its circumcircle. In a triangle, the Bankoff circle is the circle that passes through the triangle's vertices and is tangent to the sides of the triangle at certain points. This circle is named after the mathematician A. Bankoff, who studied its properties.
Apollonian circles are a fascinating concept in geometry associated with the problem of Apollonius, which involves finding circles that are tangent to three given circles in a plane. The study of these circles reveals insights into various geometric properties, including tangency, curvature, and configuration. In more detail: 1. **Apollonius' Problem**: The classical problem, attributed to Apollonius of Perga, asks for the construction of a circle that is tangent to three given circles.
In mathematics, the term **antiparallel** typically refers to vectors or lines that are oriented in opposite directions. Specifically, two vectors are said to be antiparallel if they have the same magnitude but point in opposite directions. For example, if vector \( \mathbf{a} \) points to the right (e.g.
In mathematics, an annulus (plural: annuli) is a ring-shaped object that is formed by the region between two concentric circles. It can be described in the following way: 1. **Definition**: An annulus is the set of points in a plane that are situated between two circles, typically denoted by an inner circle with radius \( r_1 \) and an outer circle with radius \( r_2 \), where \( r_2 > r_1 \).
Angular diameter (or angular size) is a measure of how large an object appears to an observer, expressed as an angle. It is typically measured in degrees, arcminutes, or arcseconds. Angular diameter is important in fields such as astronomy, where it helps to describe the apparent size of celestial objects (like stars, planets, and galaxies) from a specific point of view, typically from Earth or another observation point.
The Angle Bisector Theorem is a fundamental principle in geometry that relates the lengths of the sides of a triangle to the segments created by an angle bisector.
The AA postulate, or the Angle-Angle similarity postulate, is a fundamental principle in geometry that states that if two triangles have two angles that are equal, then the triangles are similar. This means that their corresponding sides are in proportion, and their corresponding angles are also equal.
In geometry, a point is a fundamental concept that represents a precise location in space. It has no length, width, depth, or any other dimensional attribute—essentially, it is a zero-dimensional object. Points are usually denoted by a capital letter (e.g., A, B, C) and can be represented on a coordinate system by ordered pairs or triplets (for two-dimensional or three-dimensional spaces, respectively). Points serve as the building blocks for more complex geometric shapes and constructions.
Orthogonality is a concept used in various fields, primarily in mathematics, statistics, and computer science, which describes the idea of two vectors being perpendicular to each other in a specific space. In the context of Euclidean space, two vectors are said to be orthogonal if their dot product is zero.
Euclidean plane geometry is a branch of mathematics that studies the properties and relationships of points, lines, angles, surfaces, and shapes in a two-dimensional plane. It is named after the ancient Greek mathematician Euclid, who is often referred to as the "father of geometry" due to his influential work, "Elements," which systematically presented the principles and proofs of geometry.
Elementary shapes, often referred to as basic or fundamental shapes, are the simplest geometric figures used in mathematics and design. They serve as the foundation for more complex shapes and structures. Some common examples of elementary shapes include: 1. **Point**: A precise location in a space with no dimensions (length, width, or height). 2. **Line**: A straight path that extends infinitely in both directions and has no thickness. It is defined by two points.
"Elementary geometry stubs" typically refers to short articles or entries on topics related to elementary geometry that are found in online encyclopedias or databases, particularly Wikipedia. These stubs contain basic information about a subject but are incomplete, lacking in-depth detail or comprehensive coverage. In the context of Wikipedia, a stub is a type of article that is too short to provide substantial information on its topic, but it has the potential to be expanded by contributors.
An angle is a geometric figure formed by two rays (or line segments) that have a common endpoint, known as the vertex. The measure of an angle is typically expressed in degrees or radians and represents the amount of rotation required to align one ray with the other. Angles can be classified into several types based on their measure: 1. **Acute Angle**: Less than 90 degrees. 2. **Right Angle**: Exactly 90 degrees.
Subtraction is one of the four basic arithmetic operations, alongside addition, multiplication, and division. It involves taking one number away from another. The result of a subtraction operation is called the difference. In a subtraction expression, the number from which another number is taken is called the "minuend," the number that is being subtracted is called the "subtrahend," and the result is known as the "difference.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact