The term "shape" can refer to different concepts depending on the context in which it is used: 1. **Geometry**: In mathematics, a shape is the form or outline of an object, defined by its boundaries. Common geometric shapes include circles, squares, triangles, and polygons. Shapes can be two-dimensional (2D) or three-dimensional (3D), with 2D shapes having length and width, and 3D shapes having length, width, and height.
A semicircle is a shape that represents half of a circle. It is formed by cutting a circle along a diameter. The key characteristics of a semicircle are: 1. **Definition**: A semicircle consists of the arc of a circle that spans 180 degrees and its endpoints, which are the endpoints of the diameter. 2. **Diameter**: The line segment joining the endpoints of the arc is called the diameter of the semicircle.
Reuschle's theorem is a result in the field of mathematics, particularly in graph theory. It is concerned with the properties of certain types of graphs, specifically focusing on the conditions under which a graph can be decomposed into subgraphs with particular properties.
Reflection symmetry, also known as mirror symmetry or bilateral symmetry, is a type of symmetry where one half of an object or shape is a mirror image of the other half. In simpler terms, if you were to draw a line (called the line of symmetry) through the object, the two halves on either side of the line would match perfectly when flipped over that line. Reflection symmetry is commonly found in nature and art.
The radical axis is a concept in geometry, particularly in the study of circles. Given two circles in a plane, the radical axis is the locus of points that have the same power with respect to both circles. ### Key Points about the Radical Axis: 1. **Definition**: For two circles, the radical axis consists of all points P such that the power of the point P with respect to the first circle is equal to the power of the point P with respect to the second circle.
In geometry, a "power center" refers to a specific type of point associated with circles. It is usually related to the concept of the "power of a point," which is a measure of how a point relates to a circle in terms of distances.
"Pons asinorum," which translates from Latin as "bridge of asses," is a term used in mathematics and philosophy to refer to a fundamental theorem or concept that serves as a critical point of understanding for students or learners. The term is most notably associated with Euclid's "Elements," specifically Proposition 5 of Book I, which deals with the properties of isosceles triangles. The proposition states that in an isosceles triangle, the angles opposite the equal sides are equal.
Pompeiu's theorem is a geometric result concerning the relationships between geometric shapes and their properties. Specifically, it states that if \( S \) is a bounded measurable set in the Euclidean space \( \mathbb{R}^n \), and if \( f: \mathbb{R}^n \to \mathbb{R} \) is a continuous function such that the integral of \( f \) over \( S \) is zero (i.e.
Perimeter is a term used in mathematics and geometry that refers to the total length of the boundaries of a two-dimensional shape or figure. It is calculated by adding together the lengths of all the sides of the shape.
The Parallel Postulate, also known as Euclid's Fifth Postulate, is a fundamental principle in Euclidean geometry. It states that given a line and a point not on that line, there is exactly one line through the point that is parallel to the given line.
In geometry, the term "parallel" refers to two or more lines or planes that are the same distance apart at all points and do not meet or intersect, no matter how far they are extended. This property is fundamental in understanding the behavior of lines within Euclidean geometry. ### Key Properties of Parallel Lines: 1. **Equidistant**: Parallel lines maintain a constant distance from each other, meaning the distance between them remains consistent along their entire length.
A mirror image refers to the reflection of an object or an individual as seen in a mirror. It typically appears reversed or flipped, meaning that the left side of the object appears as the right side in the reflection, and vice versa. This phenomenon can apply to various contexts, including: 1. **Physical Reflection**: When you stand in front of a mirror, your reflection is a mirror image. This reflection shows the same shape and details as you, but inverted laterally.
The term "midpoint" can refer to different concepts depending on the context. Here are a few common uses of the term: 1. **Mathematics**: In geometry, the midpoint is the point that is exactly halfway between two endpoints of a line segment.
In geometry, a medial triangle is a triangle formed by connecting the midpoints of the sides of another triangle. If you have a triangle \( ABC \), the midpoints of sides \( AB \), \( BC \), and \( CA \) are labeled as \( D \), \( E \), and \( F \) respectively. The triangle formed by these midpoints \( DEF \) is called the medial triangle.
Maxwell's theorem in geometry concerns the properties of convex polyhedra. It states that the number of vertices \( V \), edges \( E \), and faces \( F \) of a convex polyhedron are related by the formula: \[ V - E + F = 2 \] This relationship is a specific case of Euler's characteristic formula for polyhedra. The theorem is named after James Clerk Maxwell, who contributed to its formalization in the context of geometric topology.
In mathematics, a locus (plural: loci) is a set of points that satisfy a particular condition or a set of conditions. It can be thought of as a geometric shape or figure that represents all possible locations in a given space that meet specified criteria. For example: 1. **Circle**: The locus of all points that are a fixed distance (radius) from a given point (the center) defines a circle.
Here's a list of essential formulas in elementary geometry, organized by different geometric figures: ### 1.
In geometry, a line is a fundamental concept that represents a straight one-dimensional figure that extends infinitely in both directions. It has no thickness, width, or curvature, and is typically defined by at least two points. Lines can be described using a variety of properties: 1. **Definition**: A line is determined by any two distinct points on it.
In geometry, a "jack" typically refers to a shape that is formed by combining two or more geometric figures. However, the term is more commonly associated with a type of mathematical object known as a "jackknife" or "jack" in the context of certain geometric constructions or games, such as "jackstraws" or "pick-up sticks.
Internal and external angles refer to angles associated with polygons and circles, particularly in the context of geometry. Here’s a brief overview of each: ### Internal Angles Internal angles (or interior angles) are the angles formed inside a polygon at each vertex. For example, in a triangle, the internal angles are the angles that are located within the triangle itself.

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